[https://pubchem.ncbi.nlm.nih.gov/periodic-table/png/Periodic_Table_of_Elements_w_Chemical_Group_Block_PubChem.png ]
As before, while the behavior of all molecules is rooted in the orbital structure and electron dynamics, it is convenient to define broad categories of molecules that behave in similar ways. In the past and in the absence of any way to determine precise structures, molecular behavior was essentially all that previous chemists had to work with. Despite the psychological weight of all the work that has been performed making categorizations and trying to fit all known compounds into a few well-defined categories, the reality of chemistry is and always has been messy. With that in mind, let’s talk about ions, acids, and compounds.
First up, I should spell out the difference between an element, a molecule, a compound, a substance, a chemical, and however else you want to refer to things. An atom of an element has a distinct atomic number, a distinct number of protons, and in the neutral and ground state (uncharged and in the lowest possible energy electron configuration) has a distinct orbital and electronic structure. It is of course possible to have many atoms of the same element as well as different numbers of neutrons in/isotopes of the same element, but (ie) a boron atom is going to have fundamentally different bonding properties than a carbon atom or any other atom. Once you start bonding atoms together, you end up with molecules that have distinct structures, molecular orbitals, and chemical behaviors. There will of course be similarities between similar molecules, but a molecule of methane (CH4) is different than one of ethane (C2H6 or H3C-CH3) or one of propane (C3H8 or H3C-CH2-CH3). Continuing with the hydrocarbons, once you get to four carbons (C4H10) and above it is possible to have multiple configurations of the main carbon chain, so technically you would need to distinguish between butane (historically unbranched/normal/n-butane) and 2-methylpropane (historically isobutane/i-butane). However, we are now getting into the different isomers (butane, 2-methylpropane) of the same chemical formula (C4H10) instead of sticking with the idea of compounds. So, I would define a compound as a unique three dimensional arrangement of atoms, but trying to describe a three-dimensional and possibly quite complicated shape in words concisely gets difficult extremely quickly. As with atoms, you can have very many identical molecules in the same place, although in practice mixtures of similar molecules are more common unless extensive purification work has been conducted. By the time we are talking about a substance, we have progressed from a 3D picture of one unique molecule to whatever you are physically dealing with. This could be a mixture of different compounds, different compounds with trace contaminants, one compound with trace contaminants, any of the above with more than trace contaminants, etc. In practice, figuring out what is actually in the test tube/beakeflask/reaction glassware is quite difficult, and you may notice that we are at the practical level after having started in theory.
Generally speaking, I would suggest starting with IUPAC naming conventions, which are intended to include as much structural information in the name as possible, as seen with the butane and 2-methylpropane names in the preceding paragraph. In practice, nearly every specialization will have their own naming schemes that they will defend to the point of exhaustion regardless of whether or not retaining a separate naming scheme that people then have to learn makes sense. My position is that the benefits of a naming scheme that can be applied as universally as possible and be comprehended by as many people as possible is going to outweigh the inconvenience of the extra characters in 2-methylpropane versus “i-butane”. Speaking of unique naming schemes, I had to attempt to memorize several during the course of my undergraduate instruction, including dihydrogen monoxide (H2O)/carbon dioxide (CO2), the difference between nitrate and nitrite (one is NO3^-, the other is NO2^-), sodium chloride (NaCl)/disodium carbonate (Na2CO3), and a bunch of other stuff that I clearly have not retained very well. When dealing with covalently bonded compounds like water or carbon dioxide, the main way to figure out whether you have a valid structure or a false memory is to keep track of/draw out the valence electrons of each atom and make sure that they all “own” the correct number of valence electrons and are participating in an appropriate number of bonds. In charged molecules/ionic compounds/salts, there is the additional complexity of making sure that the charges end up on the correct counterions. As an example, sodium (Na) can either have a charge of 0 (neutral) or a charge of +1, while a chlorine atom (Cl) has a charge of 0 and the chloride ion (Cl-) has a charge of -1. If your structure requires chlorine to have a positive charge, you have almost certainly made a mistake. Also, the net charge on any molecule defaults to 0, so adding up all of the charges on all of the ions is another useful check. In practice, only a few ions that will be commonly encountered, and searching either the structure or the name quickly brings you to the missing information. Unless you’re in an exam, of course.
For our purposes, that is a sufficient introduction to the rules of relatively simple and mostly inorganic compounds and their naming. I have left plenty of information out, but the best way to actually learn about this is to encounter the concepts and naming schemes during the course of your normal work or exploration and doing enough internet searching to fill in most of the gaps in your knowledge rather than trying to memorize enough information to immediately identify every compound in the entire universe. We also need to get into acid-base chemistry, which suffers from a surplus of definitions. The most familiar definition is the Brønsted-Lowry definition of an acid as a proton (H+) donor, and a base a proton acceptor. In this definition, an acid’s ability to donate H+ depends on how closely the proton is bonded to the atom it detaches from, leading to a spectrum of strong and weak acids and their conjugate bases. It is important to note that all of this is taking place in water, with the protons actually being donated to water molecules to form hydronium/H3O+, which is then complexed to and stabilized by the negative (non-hydrogen) ends of adjacent water molecules. The positive charge on the hydronium complex is countered by the negative charge on the former acid that is caused by the departure of a proton without its electron. Or, an acid (HA) donates a proton to water to form hydronium (H3O+) and the deprotonated conjugate base (A-) of the acid. The net charge is still zero, the number of electrons remains the same, etc. The same thing can happen when a base (B or B-) accepts a proton from hydronium (H3O+) to form the conjugate acid of the base (HB+ or HB), although the existence of B- in solution will depend on the presence of a positively charged counterion. Complicating matters further, water will always contain some hydronium (H3O+) and some hydroxide (OH-) due to spontaneous disocciation even before any Brønsted-Lowry acids or bases are added. It logically follows that hydronium (H3O+) is the strongest acid that can exist in water and hydroxide (OH-) is the strongest base that can exist in water. The degree of acidity or basicity that can be ascribed to a substance added to water is due to the degree of dissociation – strong acids or bases will almost completely dissociate, very weak acids or bases will hardly dissociate, and everything in between.
So and in summary, Brønsted-Lowry acids or bases can only donate or receive protons in water or another suitable medium. If we instead use the Lewis definition of acids as accepting electron pairs and bases as donating electron pairs, we are well situated to get into the organic chemistry reactions. It must be said that most people will not have much contact with situations in which the concept of Lewis acids and bases adds anything to the Brønsted-Lowry definition. At the same time, if we view the protons detached from Brønsted-Lowry acids as the actually acidic component (because this is the case) and the HA “acid” as a delivery medium for the proton, we find that the Lewis definition squares perfectly well with the idea of H+ accepting an electron pair and being “donated” to another molecule, with the other molecule donating an electron pair and “accepting” the hydrogen. The Lewis definition is both more broadly applicable and focuses on the electrons as the most important part of any chemical interaction, which makes sense because chemistry is the movement or presence of electrons more than anything else. The general chemistry professor who was responsible for teaching me about acid-base chemistry was an inorganic specialist, dismissed the Lewis definition as being unimportant, and caused me several years of confusion and anxiety as a direct result.

Acids and bases

[https://pubchem.ncbi.nlm.nih.gov/periodic-table/png/Periodic_Table_of_Elements_w_Chemical_Group_Block_PubChem.png ] or [https://ptable.com/#Properties ]
If we are going off the Lewis definition of acids as electron pair acceptors and bases as electron pair donors, the problems of ion solubility (mostly H+ and OH- ions) can be appropriately distanced from the actual behavior of hydronium (H3O+) or hydroxide (OH-) complexes in water. In other words, we first ask what species exist in what concentrations in the solution of interest, then what will happen between the different species. However, we cannot completely separate the Brønsted-Lowry and Lewis definitions due to Le Chatelier’s principle, which would state that the presence of the products of dissociation tend to prevent additional dissociation events. However, if product ions start being consumed in other reactions, the effective result is to shift the equilibrium back towards the starting materials, and additional dissociation events will then become energetically favorable. The result of this is that the behavior of chemical reactions is best contemplated holistically and with a full set of executive functionality instead of being taught as a series of disconnected fragments that imply the existence of a much higher level of precision than is actually ever possible and must be stitched together by students working without the benefit of fully developed brains. As I go through the process of writing out this series of posts, I am getting the definite impression that the progress that has been made in our understanding of atoms and orbitals has mostly obsoleted the way that general chemistry is currently taught, and that the current state of teaching is centered around exams to the detriment of the students. My general chemistry education also had far too much emphasis on the Brønsted-Lowry definition of acids and bases instead of treating these as equilibrium problems.
So and before we go any farther, let’s get pH out of the way. A lowercase “p” denotes the mathematical operation of taking the negative log of a quantity for some reason, so pH is actually the negative (base 10) log of H where H is the ionic activity of “H+” in the solution of interest. As it turns out, this is actually the activity of hydronium complexes instead of lone protons, but unless you are trying to visualize what is actually happening in the solution the two can be treated as equivalent. Of course, if you’ve gotten so obsessed with applying equations to chemical processes that you are willing to ignore the three-dimensional picture, you’re probably also not doing anything of value, but anyway. In most cases, pH can be calculated with the concentration of hydronium in moles per liter instead of a more rigorous activity measurement, so in other words pH is mostly equal to -log([H3O+]). [I should also note that the difference between the concentration of hydronium and the concentration of protons is not particularly significant in acid-base problems because the protons in water will either react with other species or form hydronium. If you are calculating the concentration of protons in water at any given time, you are also calculating the concentration of hydronium.] If you’re willing to get pedantic there is a nearly infinite amount of additional complexity that can be brought in here, but I’m not emotionally invested in this and see no reason to care. Proceeding with pH=-([H3O+]), you may notice that we are only calculating the acidity of our solution and not the basicity.
However, due to the spontaneous dissociation/autoionization of water, acidity and basicity are closely related to each other. In a volume of water, the multiplication product of the concentrations in moles per liter of hydronium/H3O+ and hydroxide/OH- is a constant. At 25 degrees Celsius, this constant (Kw) is equal to 1.0x10^-14, and Kw=[H3O+]*[OH-]. In this notation scheme, the square brackets denote concentration in moles per liter, and square brackets are usually but not always moles per liter. In any case, the reason to care is that the assumptions here mostly hold true once we start adding additional chemical species to the volume of water we started with. As the number of ions in solution increase, other issues start to arise, but mostly what you need to remember is that this is a simplified model and not an absolute definition of what is happening on the molecular level. Where this model is valuable is in relating the concentration of hydronium to the concentration of hydroxide (both in moles per liter) in a mostly reliable manner, which means that if we know a value for one at a given time we can calculate the value of the other one. So, if you have a concentration of hydroxide and you want to know the pH, you can use Kw to calculate the concentration of hydronium, then take the negative base 10 log of the result to get to pH. The addition of the logarithm allows the comparison of numbers with vastly different orders of magnitude but also brings quite a bit of confusion. In any case, using these assumptions we can define interrelated pH and pOH scales to measure acidity and basicity as the density of hydronium and hydroxide in solution. You may notice that this aligns well with the Lewis definitions, although we are not considering any other possible Lewis acids or bases.
Once you get into organic chemistry and start trying to do reactions, having a trace amount of ions in your reaction mixture doesn’t get you anywhere, and all of the assumptions as previously defined get thrown out of the window. At high concentrations of ions/high ionic activities (which are mostly equivalent concepts), we get back to the idiosyncratic and non-intuitive behavior that we expect to see in chemistry. These conditions also favor the Lewis definitions, and if it seems like I am being a bit heavy-handed in mentioning the advantages of teaching the Lewis definitions to students as early as possible you would be quite correct. Fully embracing the Lewis definitions will require the more neurotic or tradition-bound individuals among the chemical community to let go of literally centuries of work that turns out not to be valid, but as before I have no particular emotional investment in Brønsted-Lowry and would much prefer to be taught the concepts in a way that actually makes sense.
In my list of topics I am supposed to cover acid-base equilibrium, which in the context of water (aqueous solutions) is how hydronium and hydroxide move into and out of solution. First looking at “HA” or a proton donor, we can either have the acidic proton attached to the conjugate base or not. The Lewis basic strength of “A-” determines how tightly the H+ is bonded and therefore how accessible it is to the surrounding water molecules. If the H+ is bonded too tightly, there is no chance of a water molecule ever removing it, and the compound is probably not going to be participating in any aqueous acid-base reactions. At this point I am really wanting to bring in some more organic chemistry concepts and talk about an example like ethanol (CH3CH2OH) as a compound with three distinct types of protons in three different chemical environments, with the hydrogen on the oxygen end (Eth-OH) as well as the two lone pairs on the oxygen being the most interesting electron pair acceptors and donors, but the current general chemistry syllabus as defined by the American Chemical Society (ACS) prevents this. Moving on to “BOH” in water, the strength of the bond between “B+” and hydroxide is also going to be important. As an example, the hydroxl group on ethanol has essentially no chance of being removed in an aqueous solution unless something quite energetic/violent happens, but the hydroxl proton can be stripped off or another proton can bond to one of the lone pairs on oxygen depending on the reaction conditions.
In the context of this post, I am basically trying to get into a decent position to talk about buffers. These are modeled by the Henderson Hasselbalch equation and are usually a combination of a weakly proton-donating “HA” with the “A-” part of that molecule paired with a positively charged counterion (counter-cation possibly). As an example cation, let’s choose sodium (Na+), which is a terrible electron pair acceptor because it is already in a noble gas valence electron configuration and adding electrons will be destabilizing. So, we can basically ignore the sodium ions unless we are interested in the total ionic activity for some reason, and at the same time the charges all balance out. If we select the correct “A-” and adjust the relative amounts of “HA” and “NaA”, we end up with a mixture that starts out at a pH that can be predicted via calculation. This is normal when adding proton or hydroxide donors to water, but where buffers are different is the ability to absorb proton or hydroxide inputs without the pH changing much. This is because of the presence of both protonated “HA” and deprotonated “A-” and is useful in situations were the molecules under study cannot tolerate large pH swings, which usually means proteins and other biological molecules. Selecting a buffer requires the concept of the constant of acidic dissociation (Ka) and the negative log of the same (pKa), but between this and Henderson Hasselbalch equation you should have plenty of keywords to play with. I am also supposed to be covering titrations here, but since these are as obsolete as Brønsted-Lowry and really shitty to have to carry out in the lab I’m not going to bother.

ph and solubility

Tips and advice for current/future IB students

Okay, so, I am going to break down this guide into the subjects which I took. Use Control F to read about the subjects you want because this guide is quite long.
SL: English A Language & Literature, Spanish Ab Initio, Mathematics
HL: Biology, Chemistry, Economics
First of all, a huge shoutout to everyone on this sub for all of the help they gave me during the IB, specifically all of those resources and all of the memes to keep me going. A special thanks to the mods who keep the place in control too :).
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English A Language & Literature SL
Paper 1:
With this paper, I cannot stress enough how much you need to PRACTICE. Practice is the absolute key to being successful on this paper. You could get literally any type of text on this paper, and for this reason you need to practice as much as possible on all of the possible text types (these can be found in the subject guide). Before the exam, try to memorise some of the conventions of each text type to show off to the examiner your text knowledge. I was a teacher who made each person in the class do a list of conventions for each text then send it to the class, but if not you may want to try and do this. I get that practice can take a ton of time, so for this reason just annotate the texts that come up in Paper 1's, you do not need to write the full essay. You also may want to make a list of all of the stylistic devices which come up, and their relevance (I have a sheet of these which I can upload if anyone wants it).
Specifically when actually writing this paper, you want to link all of your analysis to one main idea, which our teacher taught us to be the PURPOSE of the text. So, if in doubt during the exam, link things to the purpose of the text, and make sure you actually believe in the purpose that you are writing about, because if not you will struggle to avoid going on a tangent. In each of your analysis paragraphs start off with a topic sentence i.e. "X text uses Y feature to convey the purpose", then do your analysis then finish off with a link back to the purpose. If you are struggling to think of points to make in your essay, just think of the BIG 5 (Purpose, Themes, Stylistic Devices, Mood and Structure). Also, remember 1 thing, every single thing on the text is there for a reason, so you can analyse everything i.e. Pictures (I have a note sheet on how to analyse pictures as well, if anyone wants it let me know and I can upload it), Slogans, Titles, Captions, etc.
Paper 2:
First thing that I will say for this is please read the books, like there is no way around it. My teacher gave us a booklet of quotes for both texts that we studied for the exam (Miss Julie and Never Let Me Go), and it was still useless until I actually read both books. To be honest, there is nothing more valuable for Paper 2 then listening in class. When you read the books and listen to class discussion on them, you begin to understand the themes, moods, characters and plots further, and you begin to articulate your own opinions on the texts which is KEY for the exam. What you want to do ahead of the exam is make notes through specific quotes, and you want to link all of them to context. No matter which question you choose to answer, you must include context to score highly. During the exam you need to make a judgement call on which quotes that you have memorized fit the question best, and if the quotes do not fit the questions perfectly, don't worry. A big part to scoring highly on Paper 2 is your close analysis (i.e. talking about denotations and connotations of words and phrases), so if you do have to choose quotes which don't perfectly fit, you inbed analysis perfectly.
Also, ANALYSE your quotes before the exam, and memorize some of that analysis, because if you can memorize links to context and some of the more complex literary devices, it will help you when writing your essay. With your quotes, you want to be able to link all of them to at least one character, symbol and one piece of context. LitCharts can do this for you luckily, and it is really good at doing it, and I used them so much when revising for exams. Two final things before I finish the Paper 2 section: Have faith in yourself because it can screw you over when you change your strategy on the actual exam day (I learned about this from my mocks), and you do not need too many quotes to be successful, I think I had 7-8 for each book and I was fine. You want to PRACTICE as much as possible before this paper, and you do not have to write full essays, you can simply plan them and use your quotes for them.
IOC, FOA and Written Task:
Before I took this class, I absolutely hated English, and it was a huge relief to learn that you can have 50% of your final grade decided prior to even writing an exam, so take advantage of this! This means that your FOA, IOC and Written Task are incredibly important. If you nail these, you can afford to have a bad day on Paper 1 if your texts aren't too good, and it can be a source of relief if you don't think your exams went well. In your IOC, you want to prepare by looking at the extracts which your teacher has given you (if they give any), or read your book constantly and try to analyze any quote that you think is gold when reading (A good exersize for this is opening a random page of your texts, and just analysing everything). When it comes to the actual thing, I would recommend bringing 4 or 5 different highlighters into the exam, and highlighting the quotes with the theme you think that they link to, so that you have some structure set for your IOC, and then you can weave between these and make some creative points. You want to learn about your stylistic devices, links to the rest of the text and links to context as these are what can help you to score highly.
In your FOA, I'm not sure if your teacher will give you prompt on what you should do it on but if they do not, I would reccomend doing it on comparing two famous speeches. I did this with one of my best mates who I had a lot of trust in, and we compared a Winston Churchill speech to the Barack Obama Inaugural Speech. We both found this okay because the speeches have a TON of techniques inside them which you can show off in your FOA. So, if anyone were to ask me what to do an FOA on, I would say that. Just search up some of the world's most famous speeches, and choose one which interests you. No matter what topic you choose, analyse specific extracts on them for stylistic devices, aristotelian appeals (i.e. Ethos, Pathos, Logos (Which you can include in Papers 1 and 2 as well)), mood, themes and effects of what they do. Do video recorded practices before you do it and ask yourself questions on what is uncertain and what more you could include and you should be good.
Your written task on it's own is worth 20%, so try as hard as you can on making sure that you nail this completely. Our class was made to do 3 of these, and then we had to submit one, and I think doing 3 was the perfect amount. Even if you think that your first one is great, try as hard as possible on all 3, because naturally your analysis skills will get better over your time in the course so a similar amount of effort can produce better work. Plus, it gives you a choice on what you actually want to submit at the end of the course. Since you have a lot of independence on this, and it is technically not mean't to be an "essay", I would choose something that I enjoy, as you will put more effort into it. The written task I ended up submitting was on my IOC texts, as I surprisingly enjoyed writing that the most, but you have many options on what you can write it on (all the way from writing to an editor criticizing their recent article to writing as a person from your text to your family member (which is what I did)).
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Spanish Ab Initio
Paper 1:
I got a 5 in Spanish Ab Initio (1 mark off of a 6), so I do not think that I can give you the best advice ever. But basically, in my opinion, the bottom line with this is that you need to do two things: Learn a ton of vocab ahead of the exam and do practice papers (add any words which you don't understand into something like a quizlet set so that you can learn it). I just want to give some fair warning before anyone takes this class, IT IS NOT EASY and effort needs to be made to do well in the exam (After exams I realized I probably should've revised a lot more for this, so don't be like me and do small amounts of revision over the two years). The grade boundaries are really high because fluent people take the exams, so you need to have a good understanding of Spanish to get a 7. Process of elimination can be really helpful for the Paper 1 exams if you are in doubt, and during reading time you want to skim through the texts and FOCUS ON WHAT YOU KNOW rather than dwelling on what you do not understand, because that will not get you anywhere.
Paper 2:
One thing that you should probably know before you do this exam is that 12% (3/25) of the marks are just FORMATTING, so please learn how to format all of the different text types. For this exam what you want to know is your conjugations for about 6/7 tenses which you can use (Present, present continuous, future, near future, conditional, imperfect and preterite were the ones I learned), but I would say to learn tenses continuously over the 2 years so that it becomes second nature to you after a while. I didn't do this and on the exam day I wanted to conjugate some irregular verbs, and struggled to as it does not stick to memory too well. The people who got level 7's in my class also knew some more of the complex tenses such as Pluperfect and subjunctive, but you don't need to know the full tense necessarily, just memorize some general phrases in these two tenses which you can use in your writing. Doing practice papers for both paper 1 and 2 will help you to get a grasp of common types of questions and topics which also come up, so practice!
Speaking Exam and Written Assignment:
A large chunk of your final Spanish Ab Initio exam grade is, similarly to English Lang Lit, decided before you actually take the exam. So, once again, I will say take advantage of this. When it comes to the speaking exam, a lot of it does come down to your luck on the day, especially when it comes to preparing for the picture which you may recieve. What I did to prepare for this initial part of the exam was think of all of the possible kinds of photos I could get (i.e. A market, street, beach, campsite, factory, etc.) and would think of what I would say for each picture in English, then simply translate those words to Spanish and make Quizlet sets with it. Following this, for the questions part of the exam, I thought of questions in specific topic areas (Family, individuals, holidays, environment, the area you live, sports, health, etc.) which could come up (Paper 2 writing prompts can actually help you to come up with these), and write model answers to these. I may have some sheets of possible questions, if you guys would like me to upload them. Oh, 1 more thing, during your prep time for the Speaking exam, when thinking about how to descirbe the picture, divide the picture into 9 equally sized squares, and describe them one by one. This enables you to actually describe the photo but also show to the examiner that you know your words for location, so memorize location words (i.e. On the right, next to, behind, etc.).
Regarding the written assignment, it took me a long time to think of a topic which actually interested me, and that I knew that I could score highly on. I initially wanted to do one on comparing a typical football matchday in England to that in Spain, but someone in my class had taken it, so mine was on public transport. And, if you are stuck on which topic to choose, I would say do one on public transport. I scored 19/20 on my written assignment, and doing a written assignment on public transport allowed me to show off a lot of knowledge. In order to make it incredibly clear to the examiner that you are formatting your assignment correctly, I would have seperately bolded sections which say: Description, Comparison and Reflection. You must remember that the reflection is worth the most marks, so you should use most of your words there, since your word limit is so low. In your description, you only need 3 facts about your topic in the Spanish speaking country and in your comparison I would recommend doing 2 similarities and 2 differences in the cultures as your writing is more balanced then. When writing your reflection, I would use the same facts as the ones in your comparison so that your writing flows and is easier to understand. In the reflection, try to give some opinion phrases, which are both negative and positive, and try to link it to wider topic areas (so for me, that was talking about the environment).
~~~
Mathematics SL:
Paper 1 and 2:
Following learning everything on the syllabus (be sure to read the actual subject guide), past papers are your best friend. In my opinion, all of the textbooks that I came across for Mathematics SL were okay at teaching the topics, but when it came to the practice questions, they were average at best. The textbook questions just are never like the exam questions, and I feel like if I had spent more time doing past papers (starting from the very beginning), I could have finished with a level 7. The IB Questionbank is fantastic for this as it breaks down questions by topic and paper, so you know exactly what you are practising. If you can afford it, Revision Village is fantastic as well, because it does what the Questionbank does, but also breaks them down by difficulty and works you through problems. During the actual exam, check your work as you go, because it sucks to have done so much hard work on a section B question, only to find out that you made a small error in the first part.
The IB has started to like asking more obscure and application based questions in Mathematics SL now, so practice these as much as you possibly can. Also, when doing the actual exam, look at how many marks each question is worth, this can save you big time. I ended up missing out on a level 7 by one mark, and I was so annoyed to see that because I remember spending 5 minutes just staring at a 2 mark trigonometry question which was just asking about SOHCAHTOA. Wasting time on that question prevented me from answering a probability question (about 6-8 marks total) at the end of the paper, so MOVE ON if you do not understand what a question is asking. In Paper 2, you have got a calculator for a reason, so use it for all of the questions, and for questions where you do not have to actually write too much, write "used GDC" on the paper, and quickly sketch graphs as necessary, to make it clear to the examiner. On some questions which require more work, I would recommend checking and working backwards with a different method i.e. On a quadratic question which asks you to solve by completing the square, check with your graph or simple factorizing.
Internal Assessment / The Exploration:
The first thing I will say, and I believe this applies to all of the IA's is: Choose a topic which interests you. I ended up doing one on a topic which related to my HL Economics class to show some personal engagement, but I feel as though I would have done a bit better if I had chosen something which interested me more. In Maths, you really want to map out what your start point is and what you want to have learned by the end, then you can actually plan the logistics of what happens in between. It will also help you to stay motivated and avoid getting confused and stressed when writing it, which can mean that you put more effort into writing it as well.
In addition, I would say the IA does not have to be too complex, I ended up including topics which were a bit above SL level, but some people in my class scored higher than me even with just including SL material. Furthermore, I would say that once you have chosen a certain area of maths that you want to focus on, stick to it, and do not integrate more topics into it because you can really show off your use of mathematics if you have a strong focus in one area. Majority of the points in the IA are not actually specifically maths related, so make sure that you format your IA correctly, and make sure that is easy to both read and understand.
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Biology HL
Paper 1:
Okay, unfortunately it must be said, you kinda need to know everything for all 3 Biology HL papers because the topics which come up, especially in Paper 1's, vary year on year so you need to be prepared for anything. Paper 1 tests the most random areas of the syllabus, and requires you to know many small details in topic areas. To remember these specifics for this paper, I would recommend learning via quizlet sets and mnemonics (i.e. King Phillip Came Over For Gay Sex (Kingdom, Phylum, Class, Order, Family, Genus, Species) for the heirarchy of taxa (Yeah, its weird. I had the same reaction when our teacher told us it, but you remember it.)). On each of the 40 questions they test different areas of the syllabus, and now they love to test people on application points on the syllabus, so learn all of these. There are 2 general things which you can keep your eye out for: The first one being that whenever an image is shown, read the link to see if it gives any hints on the answer, you would be surprised how often it gives it away. The second being, if you know the order of the topics in the syllabus, this is typically the order in which they ask questions in Paper 1, so you usually know the first questions are on cells and the last ones are on human physiology (so if one of the options seems far fetched based on where it is found in the syllabus you know it is not true).
Paper 2:
First thing that I want to say for Paper 2 is practice data based questions, as you are doing revision for the actual exams and are memorizing content, take half an hour out of your Biology revision to just do data based questions. You need practice for those to be able to read graphs quickly, and be able to interpret many of them at once, so print them out of the past papers and just do them as you revise, because they are worth a lot of marks. SL data based questions are good to start off with because they are a bit shorter, but then you can ease yourself into the HL ones. Next, for those 3 mark questions which come at the end of the data based questions every year, learn some generic marking points which you can write if you have no clue what is going on because they are pretty similar every year (i.e. Effects in different animals aren't the same, you need more repeats, you need to test in more climates/places, etc.). For the rest of the paper, similarly to Paper 1, you just need to learn all of the material. I would personally use the Oxford Textbook to revise, complemented with The Science Codex and IB Dead websites because the Oxford textbook has a lot of extra info which you do not need to know. If you prefer to revise by watching, I would recommend Stephanie Castle, Crash Course and Alex Lee.
Although I did finish with a level 6, I was 1 mark off of a level 7, despite working at a high 5 and low 6 level throughout the course, and the one thing which made a big difference was taking all of the extended answer questions, seperating them topic by topic and compiling all of the markschemes together per specific syllabus point. The IB can only ask so many extended response questions, and by doing this and memorizing these markschemes, you get a good idea on the key words which the IB love to see, and implementing them becomes second nature to you. So, if you were to revise very last minute for your course, I would recommend doing this markscheme technique, as the people who score very highly usually do very well on their Paper 2 extended response questions. I would not recommend the Oxford Study Guide, the textbook is much better because the study guide is too condensed, and lacks details in some of the topics, for example in Chapter 5: Evolution. One more thing, make sure that you know ALL of the application points, the IB asks about them so much and when memorized they aren't hard marks to get.
Paper 3:
The one part to this paper which confused me the whole time was Section A, an area in which you could be asked about anything on the course, including your practicals. Pay attention when you do complusory practicals in class, you save a lot of time, as many people learn by doing things. Once you have done all of these practicals, what I did to revise was make a diagram of every practical and annotate it in as much detail as I could, and then on the side of it evaluate the pros and cons of the practical, and jot down its possible applications. That pretty much covers anything which could be asked about your practicals, and use the questionbank to find previous practical questions. And you know how I mentioned those application points before, well the IB has started to ask about them in Section A questions on Paper 3, so know them inside out before.
Section B for me was actually okay, I did Option D: Human Phys which our teacher had recommended and I found it very interesting. Similar 6 mark questions come up in this Option every year, and there is not too much to memorize at all. If you are confused on which option to learn, I would say learn Human Physiology. Again, here, the markscheme technique works fine to compile a bank of knowledge, and doing that with the resources that I have shown should be okay. They usually like to ask about similar things from each topic area, so when you practice past papers you get the gist of what these topic areas actually are. But, as I said with Papers 1 and 2, you just have to memorise the material here again. Make sure that you learn all of your diagrams here, as you need to in Paper 2, as well as definitions, as questions on labelling diagrams are common, and if you are completely stuck on one question, giving a few definitions can usually help you to pick up some marks.
Internal Assessment:
One bit of warning our teacher gave us before we did our IA's was don't worry if your experiment doesn't work completely, nobody's does. So, it's okay to have some errors in your experiment, and have to change your methodology a bit as long as you reflect on your changes and preliminary work in your IA. Online there are a bunch of what to include checklists, so use these as in my opinion they are pretty good and help to give your IA some sort of focus. Personal engagement marks are important, so imbed small bits of personal engagement into your IA as you are writing it, and as I had mentionned before, if you can reflect on your errors and preliminary work it shows personal engagement and reflection. The personal engagement doesn't have to be completely true, as there is only so much interest you can have in one experiment, and you want to save some pages for all of your reflection and analysis.
You want to make sure that you are plotting accurate graphs, and that the calculations associated with those data points are accurate, because those are marks that you can avoid. The page limit is quite low for the Biology IA, so do not make a title page or contents page, just number your sections as you go. I personally would recommend including statistical testing into your IA in order to do some numerical analysis of your data. You can do standard deviation on your graph's data points, and if you have space, and deem it appropriate, you could include another statistical test such as an ANOVA, which tests the relationship between variables. Just remember that the IA is worth 20%, so it is nice to have it as a safety net in case of a difficult exam.
~~~
Chemistry HL
Paper 1:
For chem, as with all 3 papers, past papers are your friend because there are some common topics which come up in multiple choice exams and if you nail down those chapters you can score highly. The chapters which you need to nail down in order to be successful are: Stoichiometry, Kinetics, Energetics & Thermochemistry and Organic Chemistry. Oh, and one more chapter, BONDING. Bonding is the chapter which the whole course is built on, and if you understand this chapter understanding everything else will become a hell of a lot easier, especially in the tougher chapters such as organic chemistry and acids and bases. But, again, you can never predict an IB exam, so revise all of the chapters, but the chapters that I named before, especially Bonding, are very common topics on Paper 1 and Paper 2, so you want to make sure that you understand them inside out. Like in Biology HL, mnemonics and quizlet sets are good to remember things, such as equations and definitions. Mnemonics are especially useful to learn periodicity, where the IB likes to ask about the most random trends in the periodic table, so you should simple memorise those as they are marks that you don't want to be losing. Make sure that you know error calculations for this paper, as the final couple of questions are usually on this area, and nail balancing equations as the first few questions are usually related to this.
Paper 2:
Like in Biology HL, you literally need to know everything for this paper because there are too many areas which have been asked about before. But, luckily for us, we have good resources that are availale, such as Richard Thornley's Youtube channel and the Pearson textbook, which are both absolute gold. Richard Thornley goes through all of the topic areas in insane detail, but explains them in a simple way, so I would recommend watching his videos for the very specific areas such as magnetism, dimers, walden inversion, etc. Memorize all of the formulae that you need to know, particularly for Acids and Bases, because the calculation questions are quite similar every year (i.e. Gibbs free energy, pH calculations with pKa values, molar calculations, empirical formula and equilibrium constants). Paper 1 and Paper 2, like in Biology HL, were back-to-back for me so learning everything for this paper does help for Paper 1 as well. There is a very large amount of material in Chemistry HL course too, so review the subject guide closer to exam time to make sure you know everything.
Make sure that you know ALL of your organic mechanisms, because you just have to memorize them, and drawing them isn't too hard once memorized. The IB also really likes asking about ligands and coloured transition metals, so learning the markscheme for those classic 3-4 mark questions isn't a bad idea as they do not change too much whatsoever. Past papers are again very helpful here, because you see the topics which come up very often in papers and what the exam board likes to ask about. Learn your periodic trends, because they will always come up and they are marks which you really do not need to lose if you have memorized the material, so just be safe and memorize all of the trends (Although the data book can give some trends away, so keep your eye out for that if you forget them). Another shoutout to the IB Dead website, which has some good quality notes for Chemistry too. VSEPR Theory is your friend as well, it comes up way to often, so make sure that you memorize what the theory comprises of, and memorize all of your bond angles as well.
Paper 3:
I did the Biochemistry option, and if you do Biology HL, do Biochemistry because it overlaps with Biology quite a bit, and a lot of that memorization that you do for Biology is really helpful for Chemistry too. For section A, similarly to Biology, you can be asked about any of your complusory practicals, so check the subject guide for which practicals these are. Like I said for Biology as well, draw annotated diagrams of each experiment, then write the method used to obtain the data as well as the equiptment, then you can critique it by listing pros and cons of the experiment itself. If you practice past papers, many of them give away these pros and cons via previous questions on experiments, so you should try and do some as you are going through the course because then its one thing less that you have to worry about revising closer to exam time.
Regarding section B, for the most part, at least of Biochemistry, it's simply just memorisation. So you kinda need to learn everything for this unfortunately. Past papers will help you with this because there are common areas which are always asked about in most papers (i.e. Hydrolysis, condensation, peptides, DNA, etc.). The markschemes for these topic areas are similar so myou can learn these for some of the longer questions, and the markscheme definitions are the ones which you need to know so do not memorise other definitions for key terms. There are some data based questions here so again doing past papers will help you to practice these kinds of questions. For both biology and chemistry, you don't need to do full past papers at once, use the Questionbank to your advantage and practice questions in specific areas you need to practice.
Internal Assessment:
Similarly to Biology HL, find checklists online on what to include as they are quite detailed and usually cover all bases. The Science Codex website has fantastic IA examples for both Biology and Chemistry, so if you are stuck on how to structure each of your IAs, or what kind of information to include, use the model IAs there as an example as they scored very highly. Just like in Biology HL, you want to make sure that you nail your calculations and polish your graphs to make sure that there are no errors in them (Be sure to include error calculations, which you then discuss in your reflection and evaluation section).
Personal engagement again is just something that you can make up a bit and try to imbed it into the IA as you are writing it, but it helps if you are doing a topic which actually interests you. The big advantage for the Chemistry HL IA is that you don't have to do statistical testing like you can in the Biology HL IA, so it saves you space which you can use instead on calculating error. Make sure that you try quite hard on the IA, because with Chemistry HL exams they can be so unpredictable and difficult sometimes that it's nice for something to be there to help you in case the exam day isnt the best.
~~~
Economics HL
Paper 1:
This paper is worth 30%, and with practice and past papers, is an exam which you can do very well on. Before I begin talking about anything else, for everything in Economics, even the IAs, use the Cambridge Revision Guide (Economics In A Nutshell), it's possibly one of the best revision guides I have ever used! So this paper is Micro and Macroeconomics, and to do well on the 10 and 15 mark questions, you need to memorise content from the revision guide. For anything that you do not understand in this book, or for extra detail, use EconPlusDal. Both of those resources together are insanely detailed but explained concisely enough that it is easy to follow and understand. The only hard work for this paper is finding real world examples (yes, they are kinda important, though you can make them up a bit if they sound realistic), so as you learn topics I would just search up that respective topic on Google, find some statistics and data to do with it and compile it in a document which is extensive before you sit the actual exam paper. All of the diagrams that you need to know are in the revision guide, and use a few diagrams in each of your responses, in order to visualise the theories which you are referring to.
In your body paragraphs to your responses, I used an acronym called DEED (Define, Explain, Example, Diagram), and that really helped to structure my answers to make sure I was hitting all of the points on the generic markscheme. However, in your 15 mark questions, where economic synthesis is also required, I used the acronym CLASPP (Conclusion, Long term + Short term, Assumptions, Stakeholders, Priorities, Pros + Cons) as that would cover all of the aspects of the synthesis for me. In Paper 1s every year, there is usually one Theory of the firm question in Microeconomics and one which is not Theory of the firm, so if you can nail down your knowledge on Theory of the firm, you typically have a nice question which you can answer most years (as there is only so much that they can ask on both aspects of Theory of the firm, although they do prefer to ask about market structures).
Paper 2:
This paper is also worth 30%, and I found it harder to revise for, because I absolutely despised Development Economics. Nonetheless, as I said with Paper 1, and as I will say with Paper 3, the Cambridge Study Guide is amazing to revise for this paper. In addition, since you do not need real world examples to complement your responses here, everything that you need to know is in that book. In this paper you dont have to worry as much about sticking to DEED and CLASPP, although you could use DEED on your 4 and 8 mark questions if you deem it to be an appropriate place to use it, but make sure ALL examples are from the text, as most of the marks come from there. Seriously, have a look at the markscheme to one of those 8 mark questions, you would be very surprised to see how 80% of those marking points are simply copying what is actually written inside that text booklet, so use it as much as possible!
Regarding those random definitions at the start, I would recommend just learning all of the terms in the glossary of the Cambridge Study Guide, as those definitions are very similar to the ones which usually appear in the markschemes, and aren't too long to learn (Use Quizlet if you want some more active revision!). For the 4 mark questions, do not forget Micro and Macroeconomics for Paper 2, as they can still be asked about, especially the Macroeconomics diagrams. Including some of the information from the passage in your 4 mark questions can add some more detail, and despite the question not explicitly saying to do it, it often helps to secure 4 points instead of just 3.
Paper 3:
I actually really liked this paper, and I believe that it is possible to score 100% on this paper, or at least close to it, if you just practice. Unfortunately, there is no formula booklet or anything in Economics HL to help you when writing this exam, but all of the equations you need to know are in the Cambridge Revision Guide, so learn your material from there. Regarding the 4 mark questions which you will get, they do repeat over time as there is only so much which can be assessed in this paper, so doing past papers will teach you which kinds of phrases to include in these 4 mark questions and which of these 4 mark questions usually comes up. Refresh reading points off of graphs and using those values to plug into equations to get answers, and using multiple equations to find your answers. For a lot of the small bits which have been asked before such as drawing MR curves or explaining why a profit maximisation would attract firms into a market is explained by EconPlusDal very well, so use his videos once again if you do not understand anything. If you don't think that your Paper 1 or Paper 2 went very well, Paper 3 is the paper which is there to help you out, and if you practice papers and learn all of your equations for this paper you should be good.
Internal Assessment/ Portfolio:
In Economics HL, you have to write 3 different mini-IAs, each 750 words max, which all combine to form a portfolio worth 20%. To start, I would recommend that you should do your third Economics HL IA in International Economics above Development Economics, because your International Economics article options are usually quite good compared to Development, and you can include more diagrams in International Economics. Generally speaking, focus most of your words in each of your IAs on your synthesis, because about 7 of the 15 marks on each of the IAs has something to do with the synthesis, and 2 extra marks for application, so you want to make sure that you nail that analysis really well.
Economic diagrams are key, so use them to talk about the theory related to the article as well, because then you hit two birds with one stone. In addition, I would recommend that you choose an article which talks about a problematic situation, compared to one which talks about a positive economic situation, because you can suggest more solutions and have more analysis when there are problems which need to be ammended. Other than that I would say that define your key terms well (The resources I have said do this for you), and bold key terms as you use them to make it very clear that you are using them.
~~~
Well that's my guide done, hope you guys found it helpful :) If you have any questions just reply in the comments or drop me a PM and I'll respond as best as I can to you. Once again, thanks so much to this legendary sub for all of the help they gave during the IB exam period.
EDIT: Reddit didn't let me do a post with everything in it, so I will post a part two later with my advice on TOK, EE, CAS and some extra sections for people who want to apply for Medicine in the UK

AP Bio Guide (Units 8 in comments)

Part I: Destiny's Main Logo is the Y-Goblet & How it's chemical cocktails reveal everything (The OXA Machine + Way Way More) (Ultra Extreme Deep Lore)

Preface: /////////

Ghost Fragment: Darkness 3 - From Toland The Shattered
https://www.ishtar-collective.net/cards/ghost-fragment-darkness-3#toland-the-shattered
I drive myself to the edge of madness trying to explain the truth.
It's so simple. Elegant like a knife point. It explains - this is not hyperbole, this is the farthest thing from exaggeration - EVERYTHING.
But you lay it out and they stare at you like you've just been exhaling dust. Maybe they're missing some underlying scaffold of truth. Maybe they are all propped on a bed of lies that must be burned away.
Why does anything exist?
No no no no no don't reach for that word. There's no 'reason'. That's teleology and teleology will stitch your eyelids shut.
Why do we have atoms? Because atomic matter is more stable than the primordial broth. Atoms defeated the broth. That was the first war. There were two ways to be and one of them won. And everything that came next was made of atoms.
Atoms made stars. Stars made galaxies. Worlds simmered down to rock and acid and in those smoking primal seas the first living molecule learned to copy itself. All of this happened by the one law, the blind law, which exists without mind or meaning. It's the simplest law but it has no worshippers here (out there, though, out there - !)
HOW DO I EXPLAIN IT it's so simple WHY DON'T YOU SEE

(Clue in Book Confessions Entry III to Toland mentioning The Blind Law of Atoms aka WHY CAN'T WE SEE)

Book Confessions: Entry III
https://www.ishtar-collective.net/entries/entry-iii#book-confessions
We are all losing hope, but as long as we are still losing it, then it has not run out. Psions are said to have no sense of humor, because humor comes from the unexpected, and we are clairvoyant. Well, we were not clairvoyant enough to expect the coup, so I suppose we must be blind enough to retain a sense of humor, and I can still laugh at our predicament: the loyal retinue of the Curious Emperor, the Emperor of Joyous Excess, marooned in absolute nothingness.

The Scientist: Freeborn Otzot, Psion Savant https://www.destinypedia.com/Cabal_Booklet
Centuries after we destroyed the Psions' clairvoyant OXA Machine, word reached me that it had been rebuilt on the moon of Brand. The Evocate-General sent her ships to bomb the moon. In my imperial forgiveness, I stopped her ships. I asked myself: who but a true genius could reconstruct the OXA? Who but a Psion who craved the OXA's power to see the unseen? Surely we could use that mind!
I invited the builder to join me at a fete in her honor. She was called Otzot, freeborn Psion, and she glowed with the power of her thoughts. She said, "Is this not Calus's new Empire, an empire of achievement? Can't the Psions grow fat in thought, as you grow fat with power?"
I said, you have a deal! I name you Imperial Dreamer, and you will have all that you need. All of us are stronger when we join hands in song - Cabal and Psion, Sindû and Clipse, Arkborn and all the others.
If only I could have sensed her thoughts, as she so ably sensed mine. When I moved to free the indentured Psions, I threatened Otzot's superior status as a freeborn. She joined the conspiracy against me. She used the OXA to transmit messages in secret - the military's plans for their coup.
Otzot must die.
She can sense the hostility and focus of an assassin. Somehow you must reach her undetected. Approach her in joy and trust, as I once did. Then you have hope.

https://youtu.be/GuJuRp98OuM?t=421
The end of The Insight Terminus Strike, were Otzot is being tracked by a reflection of Maya Sundaresh#12 from the Ishtar Collective on what the OXA Machine is and the information it contains.

The Sundaresh Experiment 13-R https://www.ishtar-collective.net/entries/the-sundaresh-experiment-13-r#maya-sundaresh
Ishtar Collective research led to places unexpected, unexplored, and in some cases unsanctioned.
Esi: Is that… radiolarian fluid?!
Sundaresh: Close the bulkhead, Chioma.
Esi: Where did you even—
Sundaresh: The excesses from Shim's siphons were just being discarded. This is better.
Esi: And you're using it as, what? A propellant?
Sundaresh: A coolant. If the Vex decide to simulate things in physical space such that we can experience them natively, we must understand more than just their physiology. We are too focused on the abstract and the theoretical and the simulated, love. We are scientists, yes, but Humans also make tools.
Esi: That meditation sim really had an effect on you.
Sundaresh: Hush.
Esi: A ship built with repurposed Ishtar construction materials, integrating Vex technology almost as an afterthought.
Sundaresh: You disapprove.
Esi: The last time I questioned an idea like this, it ended up saving us from simulation purgatory. I would be a fool to disapprove.Sundaresh: Then come here and let's celebrate.

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Introduction to the Chemicals and Atomic Structures that make up the Universe in Destiny (What the Light and Darkness actually are)
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!PAY SPECIAL ATTENTION TO BOLDED ITALICS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
(Thread Theme and Inspiration for this detective work) : )
https://youtu.be/oUen2-zLDG8

Part I: The OXA Machine
- OXA (definition) - indicating that a chemical compound contains oxygen, used esp to denote that a heterocyclic compound is derived from a specified compound by replacement of a carbon atom with an oxygen atom
https://www.collinsdictionary.com/dictionary/english/oxa

(from above in greater detail)
https://en.wikipedia.org/wiki/Heterocyclic_compound
Heterocyclic Compounds -
A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s).[1] Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and applications of these heterocycles.[2]
Examples of heterocyclic compounds include all of the nucleic acids, the majority of drugs, most biomass (cellulose and related materials), and many natural and synthetic dyes**.** 59% of US FDA-approved drugs contain nitrogen heterocycles
Although heterocyclic chemical compounds may be inorganic compounds or organic compounds, most contain at least one carbon. While atoms that are neither carbon nor hydrogen are normally referred to in organic chemistry as heteroatoms, this is usually in comparison to the all-carbon backbone. But this does not prevent a compound such as borazine (which has no carbon atoms) from being labelled "heterocyclic". IUPAC recommends the Hantzsch-Widman nomenclature for naming heterocyclic compounds.
Heterocyclic compounds can be usefully classified based on their electronic structure. The saturated heterocycles behave like the acyclic derivatives. Thus, piperidine and tetrahydrofuran are conventional amines and ethers, with modified steric profiles. Therefore, the study of heterocyclic chemistry focuses especially on unsaturated derivatives, and the preponderance of work and applications involves unstrained 5- and 6-membered rings. Included are pyridine, thiophene, pyrrole, and furan. Another large class of heterocycles are fused to benzene rings, which for pyridine, thiophene, pyrrole, and furan are quinoline, benzothiophene, indole, and benzofuran, respectively. Fusion of two benzene rings gives rise to a third large family of compounds, respectively the acridine, dibenzothiophene, carbazole, and dibenzofuran. The unsaturated rings can be classified according to the participation of the heteroatom in the conjugated system, pi system.
Heterocyclic Compounds Can Have up to 9 Atom Rings (I think this another clue with 9 entries in this lore book, plus the actual Nine. merely a clue that were on the right track)

All of the items that Match places into the Y-Goblet in the entries of the Confessions Lore book are derivitives of a OXA-Heterocyclic Compound as explained in detail below

History of Heterocyclic Chemistry
The history of heterocyclic chemistry began in the 1800s, in step with the development of organic chemistry. Some noteworthy developments:[6]
Piperidine https://en.wikipedia.org/wiki/Piperidine
this chemical in real life is used to make PCP or angel dust the illegal drug, but since it's part of the OXA machine's actual molecular mechinations, it inferrs the examination of the way Ghost mentions how insanely aggressive Psions are in Psionic Potential mission on Mars when talking about their behavior. Much like being on that drug.

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1818: Brugnatelli isolates alloxan from uric acid
- Alloxan https://en.wikipedia.org/wiki/Alloxan
sometimes referred to as alloxan hydrate, refers to the organic compound with the formula OC(N(H)CO)2C(OH)2. It is classified as a derivative of pyrimidine. The anhydrous derivative (OC(N(H)CO)2CO is also known as well as a dimeric derivative. These are some of the earliest known organic compounds. They also exhibit a variety of biological activities.
- Pyrimidine https://en.wikipedia.org/wiki/Pyrimidine
In March 2015, NASA Ames scientists reported that, for the first time, complex DNA and RNA organic compounds of life, including uracil, cytosine and thymine, have been formed in the laboratory under outer space conditions, using starting chemicals, such as pyrimidine, found in meteorites. Pyrimidine, like polycyclic aromatic hydrocarbons (PAHs), the most carbon-rich chemical found in the universe, may have been formed in red giants or in interstellar dust and gas clouds.
(Interstellar dust hmmm, very very interesting eh : ) )

(Book Confesssions: Entry III) https://www.ishtar-collective.net/entries/entry-iii#book-confessions
I think he feels small. Most of the universe is nothing, and he is nothing to it. This scar in our galaxy was cut long before he was born.
I drew the Y-goblet in the dirt of a garden today. I used my finger, not my mind, so that no one would feel it. My faith was exterminated long before my people met the Cabal, in a way so total and vicious that I do not think a people without psionics could understand the pain.
My ancestors were the strongest secret-keepers in the universe. I know this because they survived long enough to give birth to me. I don't know how they did it, because every time I look another Psion in the face I see the Y-goblet, the holy cup into which our minds were poured.
What if Calus knows I'm losing my faith in him? What if I'm the poison that makes him wilt?

(The Strongest Secret Keepers were the prehistoric Psions, the link to Savathun's ploy from Truth to Power)

(Truth to Power: Thank You) https://www.ishtar-collective.net/entries/thank-you#book-truth-to-power
"With this tribute, I shall undertake a mighty work. A real humdinger of a scheme. I'm going to refinance my entire existence. I'm going to move from an existential economy based on the accumulation of violence to an existential economy based on the accumulation of secrets and the tribute of failing-to-understand-me. I shall name this tribute of failing-to-understand IMBARU, for it shall be as formless as the mist."
Imbaru - means enchantment / Dul - a little town called Josefuv Dul in the Czech Republic

Dul means loop
Josefuv is czech for Josef which means may God increase

God Loop

Josefuv Dul aka Trostland
https://en.wikipedia.org/wiki/Josef%C5%AFv_D%C5%AFl_(Jablonec_nad_Nisou_District))

http://josefuvdul.eu/wp-content/uploads/MG_5002-1024x683.jpg
http://josefuvdul.eu/

History
Beginning in the year 1690, Maximilian II Emanuel populated the area with German immigrants. In 1701, the city of Karlsberg was founded by the Desfours family, who were known for the estates of Groß Rohosetz and Morchenstern. The new village was known for producing glass and crystal products.[4]#cite_note-josefuvdul-4) Karlsberg was divided into Untermaxdorf, Karlsberg and Josefsthal in 1827. Fifty years later Untermaxdorf and Antoniwald were incorporated.
The Munich Agreement permitted Nazi Germany's Adolf Hitler to annex the area in 1938 into what he called the Sudetenland. Shortly thereafter Karlsberg was dissolved becoming Obermaxdorf and Antoniwald. Josefsthal and Untermaxdorf formed a new community named Iserwald. Following World War II, in 1945, the town returned to Czechoslovakia and the German inhabitants were expelled under the terms of Beneš decrees.
Church
The Josefův Důl church was built between 1862 and 1865 in a neo-gothic style. Its construction was partially funded by a lottery and 4000 gold pieces were collected. The ceremonial laying of the foundation stone was held in September 1862. The church tower is 45 metres (148 ft) high, the interior fittings house three valuable altar paintings by Wilhelm Kandler.
https://en.wikipedia.org/wiki/Josef%C5%AFv_D%C5%AFl_(Jablonec_nad_Nisou_District)#/media/File:Kirche_Josefuv_Dul.jpg#/media/File:Kirche_Josefuv_Dul.jpg)
Etymology: Joseph's valley,[1]#citenote-1) Joseph's Mine[[2]](https://en.wikipedia.org/wiki/Josef%C5%AFv_D%C5%AFl(Jablonec_nad_Nisou_District)#cite_note-2)Motto(s):
The gateway to Jizera Mountains

https://upload.wikimedia.org/wikipedia/commons/1/17/Josefuv_Dul_JN_CZ_CD_Class_810_in_1994.jpg
Josefův Důl railway station

https://en.wikipedia.org/wiki/Josef%C5%AFv_D%C5%AFl_dam
Jusefuv Dul waterway dam
https://en.wikipedia.org/wiki/Josef%C5%AFv_D%C5%AFl_dam#/media/File:Talsperre_Josefsthal_1.jpg

hmmmm looks extremely familiar eh.....
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1832: Dobereiner produces furfural (a furan) by treating starch with sulfuric acid
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1834: Runge obtains pyrrole ("fiery oil") by dry distillation of bones

Pyrrole https://en.wikipedia.org/wiki/Pyrrole

History
Pyrrole was first detected by F. F. Runge in 1834, as a constituent of coal tar.[6] In 1857, it was isolated from the pyrolysate of bone. Its name comes from the Greek pyrrhos (πυρρός, “reddish, fiery”), from the reaction used to detect it—the red color that it imparts to wood when moistened with hydrochloric acid
Reactions and reactivity
Due to its aromatic character, pyrrole is difficult to hydrogenate, does not easily react as a diene in Diels–Alder reactions, and does not undergo usual olefin reactions. Its reactivity is similar to that of benzene and aniline, in that it is easy to alkylate and acylate. Under acidic conditions, pyrroles polymerize easily, and thus many electrophilic reagents that are used in benzene chemistry are not applicable to pyrroles. In contrast, substituted pyrroles (including protected pyrroles) have been used in a broad range of transformations

(Book Confessions: Entry III) https://www.ishtar-collective.net/entries/entry-iii#book-confessions
By the mind of Match. Upon the Leviathan, resigned to its course. Today I fill the Y-goblet with powdered bone, so that my ancestors may dry their ink. My every thought and purpose for my Emperor, Calus, once sovereign.

(Book Dust: The Bone) https://www.ishtar-collective.net/entries/the-bone#book-dust
Ikora Rey makes it fly away. "You weren't after that bone. It was after you. Did you make a wish, Lavinia? Did you ask to know about the Nine?"
She tries to explain that she didn't, that she only wanted to track the bone back to its source (Venus, hopefully), and to learn why the Nine needed the Ahamkara.
"Why do you think the Nine needed Ahamkara?" Ikora asks, dangerously.
"To make wishes," Lavinia pants. "Xûr didn't appear in the Tower until the end of the Great Ahamkara Hunt. Whatever they used to get from the Ahamkara..."
She leaves it unsaid: maybe the Nine are now getting it from Guardians.
Ikora rubs her brow. "I can't stop you. But if you keep looking, I can't protect you from the consequences."
"Help me!" Lavinia begs. "There's something here! Something that connects everything, the Trials, and the Ahamkara, and the Guardians, and the Nine. There are things the Consensus knows about Ghaul's attack, things they haven't told us—"

(Book Dust: The Gate) https://www.ishtar-collective.net/entries/the-gate#book-dust
Lavinia swears and beats her suited fist against her helmet. She's trapped in Cocytus! The last time the Awoken trapped anyone here, those poor souls went utterly insane. The doomed crew of the Dead Orbit scout ship Sophia called this place A113, an innocent catalogue number; they had no idea that the gates aboard—once a Golden Age experiment—had been captured by the Hive deity Crota. Those gates consumed them all.
Now Crota is gone, and Lavinia has gambled everything that the portals have fallen into other hands. Ahamkara make the unreal real—Calus's ship is surrounded by a halo of unreal dark matter, like a ring of probing hands, Guardians can manipulate reality itself—there is a pattern here, a story, and it leads to Cocytus, to what these gates might do.
"Logs." She pages frantically through the observations left by the Awoken sentries once stationed here. Cocytus was abandoned when the Red Legion attacked, all its defenses scavenged to reinforce Vesta. "What came out of the gate? What did you see?"
//EVENT 1 TIME 00:00:00 Portal 3 emitted a hydrogen nucleus. Over 72 hours, the emissions developed from diatomic hydrogen to nitrogen, carbon, oxygen, water, and simple organic molecules. At the 80-hour mark, a pellet of thick black hydrocarbon tar. Until 82:34:15, the gate emitted tar containing complex monomers and polymers—
"Come on!" Lavinia barks, paging ahead. "Come on, damn you, give me something real! Give me the Nine!"
//EVENT 1 TIME 524:03:11 Portal 3 emitted a living organism. Death was immediate. Autopsy team reports a spherical body, radius one point one meters, surfaced in hydrocarbon tar. Deep, evenly spaced "throats" converged on a central cavity perhaps intended to serve as lung and stomach. The body consists of an undifferentiated tissue of primitive cells. A basic spasm reflex forces air down the throats. Without enzymes to catalyze metabolism, the organism could not survive. Cell death occurred instantaneously throughout the mass. There were no provisions for self-repair or reproduction.
Lavinia reads this again, horrified and fascinated. Something on the far side of the gate is learning to assemble atoms, molecules, even haphazard life... something from a world of darkness and dust, probing its way into our structured existence, trying to cobble together a message, an emissary, a body...
The Nine are on the far side of this gate. She's sure of it. She's found them.

A113 isn't just a Pixar meme

Nihonium https://en.wikipedia.org/wiki/Nihonium
Nihonium is a synthetic chemical element with the symbol) Nh and atomic number 113. It is extremely radioactive; its most stable known isotope, nihonium-286, has a half-life of about 10 seconds. In the periodic table, nihonium is a transactinide element in the p-block. It is a member of period 7 and group 13 (boron group).
Nihonium was first reported to have been created in 2003 by a Russian–American collaboration at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, and in 2004 by a team of Japanese scientists at Riken in Wakō, Japan. The confirmation of their claims in the ensuing years involved independent teams of scientists working in the United States, Germany, Sweden, and China, as well as the original claimants in Russia and Japan. In 2015, the IUPAC/IUPAP Joint Working Party recognised the element and assigned the priority of the discovery and naming rights for the element to Riken, as it judged that they had demonstrated that they had observed element 113 before the JINR team did so. The Riken team suggested the name nihonium in 2016, which was approved in the same year. The name comes from the common Japanese name for Japan (日本 nihon).
Very little is known about nihonium, as it has only been made in very small amounts that decay away within seconds. The anomalously long lives of some superheavy nuclides, including some nihonium isotopes, are explained by the "island of stability" theory. Experiments support the theory, with the half-lives of the confirmed nihonium isotopes increasing from milliseconds to seconds as neutrons are added and the island is approached. Nihonium has been calculated to have similar properties to its homologues boron, aluminium, gallium, indium, and thallium. All but boron are post-transition metals, and nihonium is expected to be a post-transition metal as well. It should also show several major differences from them; for example, nihonium should be more stable in the +1 oxidation state than the +3 state, like thallium, but in the +1 state nihonium should behave more like silver and astatine than thallium. Preliminary experiments in 2017 showed that elemental nihonium is not very volatile); its chemistry remains largely unexplored.

The Aphelion are made of Nihonium when they attacked the Awoken on Bamberga

(Book The Dreaming City: Bamberga) https://www.ishtar-collective.net/entries/bamberga#aphelion
SUMMARY OF SBU APHELION INCIDENTS FOLLOWS BELOW.
*** EVENT 2PAL-A :: OTDR-4-REL ***
INFORMATION RECEIVED APR 09-18T02:29:45+00:00 FROM PALADIN NOLG, CONSIDERED SOBER, DEPENDABLE, NOT OF FANTASY. NOLG REPORTED "A GLOWING CREATURE" ON EXT OF HIS SHIP "RETRIBUTION" MOMENTS BEFORE ROUTINE NLS JUMP.
"RETRIBUTION" FDR SHOWED RAD SPIKE (5 SIGMA) ON TEPC, CPDS, AND RAM. CPD SHOWED NO EFFECT. ON RECOMMENDATION OF K WADJ, NOLG WAS QUARANTINED UNDER TECHEUN SUPERVISION FOR 1 MONTH. "RETRIBUTION" DECOMMISSIONED, SET ADRIFT BEYOND REEF.
A SAR FLEET FOUND THAT THE AMESTRIS WAS UNSAFE TO BOARD DUE TO RADIOACTIVE SURFACE CONTAMINATION. SAR DEPLOYED MULTIPLE CROW DRONES FOR INTERIOR SURVEY. NO EVIDENCE OF HULL BREACH WAS FOUND. NO EVIDENCE OF MALTECH DETONATION WAS FOUND. NO EVIDENCE OF HOSTILE ALIEN INTERFERENCE WAS FOUND. NO EVIDENCE OF INTERNAL SABOTAGE WAS FOUND. NO SURVIVORS WERE FOUND.
AMESTRIS ABANDONED, SET ADRIFT BEYOND REEF.

Important Cutscenes Below to connect this stuff:

https://youtu.be/5HmV_mKzWmo

https://youtu.be/2ehZORTn3MM (Sjur Eido, the only Awoken to survive an attack from The Aphelion)

The Nine saved Sjur Eido by absorbing all the surrounding Helium-4 around her, since this is what the actual "Darkness" is has she explored Anthenaeum World X

Aphelion (definition) - (astronomy) The point in the elliptical orbit of a planet, comet, etc., where it is farthest from the Sun.
https://en.wiktionary.org/wiki/aphelion

Skin Basics 1.6.1 - The Acid Mantle - Sweat and Sebum Skin Basics 1.6.1 - The Acid Mantle - Sweat and Sebum

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Disclaimer

I am not a doctor! Please don’t sue me, I’m already poor!

Lesson 1.6.1: The Acid Mantle

Welcome back, lovelies! Today, I will finally be delivering on the topic I have been unintentionally postponing for the past who-knows-how-long:

*: ͓ °✧ the acid mantle ✧° ͓ : *

But did you notice that pesky “.1” stuck in the title? You guessed it -- this subject is getting at least one more post all to itself.
So for now, we’ll be focusing our attention on the substances responsible for making the acid mantle, and the glands responsible for making these substances!

Prerequisites:

1.1 - Layers of the Skin
1.2.1 - Skin Cells - Function, Structure & Protein Babies
1.2.2 - Skin Cells - Hypodermal Specialized Cells (not required, but recommended)
1.2.4 - Skin Cells - Epidermal Specialized Cells, pt. 2 (not required, but recommended)
1.4 - Acids and Bases
1.5 - The pH Scale

What Is The Acid Mantle?

The surface of your skin is acidic, and it has something to do with sweat. That was about as much as we knew on this topic back in 1892, when it was first brought up in a published paper.
Luckily, along came 1928, when German dermatologist Alfred Marchionini and his teacher, H. Shade, published a paper that gave us a better description of this thing they called the “säuremantel”, an acidic film on the surface of the skin that discouraged the growth of bacteria.
With this slightly newer paper unveiling the potential relationship between skin acidity and your overall health, it paved the way for scientists to give more of a crap and start studying it a bit more closely.
We now lovingly refer to this film as the acid mantle.

When you are first born, the pH of your acid mantle isn’t all that acidic, measuring in at about 6.4. It’s not until your third or fourth day of existence that the pH will drop down to about 4.9.
Now that you’re older, it probably still has an acidic pH, measuring somewhere between 4.0 and 5.9. That low pH is what gives this film a starring role in your innate immune system, as it is your body’s first line of defense against pathogens.

But while acting as your skin’s bacterial bouncer might be the role your acid mantle is most famous for, don’t start typecasting this guy -- your acid mantle has a fantastic resume:

It works as a barrier, being one of the many tools your skin uses to prevent water from escaping (because we all know that skin likes to be a moisture hog).
It plays a heavy supporting role in making sure your lipid barrier is in tip top shape.
And it helps to protect you against the damage caused by free radicals.

In today’s lesson, we’ll just be focusing on the junk that forms the acid mantle. But keep these jobs in mind because next time, we will be learning about how your mantle actually performs all of these tasks.

Eccrine Sweat Glands

It feels like we’ve come a long way since the last time we talked about integumentary accessory structures. ^{Aw, I should start scrapbooking about how far we’ve come. ♡}
But now that three of these structures have finally landed a starring role in our lesson, it’s about time we give them more than just a couple of wimpy little paragraphs, don’t you think?

As you might remember, your sweat glands come in two flavors: eccrine and apocrine.
Eccrine glands are the type you are most familiar with, as they are the type that adorn your face and the majority of your body. These are also the ones I mentioned in our first lesson that look like knotted spaghetti noodles in your dermis that reach up to the top of your epidermis.

Fig. 1, Eccrine Gland Drawing

Fig. 2, Eccrine Gland Microscope Slide

The knotted portion is called the secretory coil, and is actually a cul-de-sac -- it doesn’t have an input, just an output. The input is actually handled by the cells that line the inside of the coil, which secrete the sweat into the gland. Some of the cells here can contract as well, which is what pushes the perspiration out of the noodle instead of letting it just...sit there.
The noodly portion is known as the sweat duct. The cells here will reabsorb some of the electrolytes in the sweat that had previously been secreted into the coil, leaving your sweat just slightly less salty than it would've been.
The purpose of sweating from these glands is to help regulate body temperature. When you sweat, the cool substance sits on your warm skin’s surface, which helps it to cool down.
The sweat that comes from these glands has a pH between 4.0 and 4.5, and is near 99% water, with the remaining 1% being a cocktail of urea, lactate, sodium, chloride, and potassium.

Urea

Urea might sound similar to another word you know...urine! That’s because urea is the byproduct of cellular waste, so the body needs to get rid of it by peeing or sweating it out.
Its chemical formula is CH₄N₂O, which means it has two NH₂ groups joined by a carbonyl group (which is just a carbon that’s double-bonded to an oxygen), like this:

Fig. 3, Urea
^{You don’t see a C for carbon in this picture because it’s assumed that the pointy part of the V shape that’s connecting the two N’s is the carbon. The = connecting that point to the O is the double-bond.}

Maybe NH₂ sounds a little familiar as well. Perhaps you’re thinking of NH₃ from our acid and base lesson, which is the chemical formula for ammonia. Well, funnily enough, urea is made when your liver breaks down ammonia!
Ammonia is produced by the cellular breakdown of amino acids, but as you know, ammonia is kind of a dangerous chemical. So your liver handles all this junk by consuming two ammonia molecules and one carbon dioxide (CO₂) molecule, then converting them into urea. Makes sense when you see urea happens to contain all of the elements that make NH₃ and CO₂, doesn’t it?

Lactate

No, it has nothing to do with nursing a baby. Lactate production is the result exercising!
So, you breathe, right? ^{Cool, me too!} Breathing is your body’s preferred way of creating energy, because the oxygen you’re bringing in is super convenient for your cells to access. When your cells use oxygen to create energy, it is called aerobic respiration.

Fun Fact: This is where aerobic exercise gets its name from! Aerobic exercises, like walking, jogging, swimming, and cycling, get you breathing more. This heightened level of oxygen input is being used by your cells to quickly produce the energy they need to keep up with the workout, so you can continue to walk, jog, swim, or cycle for prolonged periods of time.

But when you engage in a much more strenuous activity, like when you decide to pump some iron instead of hitting the treadmill, your cells end up needing to produce energy faster than the rate at which they’re receiving oxygen. When this happens, they’ll substitute the oxygen in their energy recipe for a different ingredient -- glucose (sugar). When your cells use something other than oxygen to produce energy, it’s known as anaerobic respiration. (And strength training is a type of anaerobic exercise. While you might be able to jog for an hour, you certainly couldn’t do bicep curls for an hour.)
The glucose is broken down by your cells into something called pyruvate. The pyruvate is then converted into lactate, and that lactate allows your cells to continue breaking down glucose while you’re still exercising.

By the way, if you are a brethren of /swoleacceptance, you might come across the occasional fitness article using lactic acid interchangeably with lactate. (And if you aren’t praising Brodin, you might recognize it as an AHA!)
So let me clarify that lactate is not the same thing as lactic acid. Your body does not make lactic acid, it makes lactate.
They are definitely related, though! Lactate is the conjugate base of lactic acid, and if you were paying attention during lesson 1.4, you’ll know that this means lactate is the chemical result of lactic acid that has dissociated and lost an H⁺. So go ahead and slap someone with knowledge the next time you visit the bodybuilders forum! ^{Don’t do this in person, though. I wouldn’t want you to be on the receiving end of some roid rage.}

Sodium, Chloride, and Potassium

Why did I lump these three together? Because they are all electrolytes. Electrolytes are named such because they are minerals that are either positive or negative ions, giving them an electrical charge.
Sodium regulates the amount of water in your body, and it is required to help generate the electrical signals that allow your various bodily processes to talk to each other (like when your nervous system is talking to your brain about how it didn’t like when you touched the stove). Potassium regulates heartbeat and muscle function -- too much or too little potassium can result in an irregular heartbeat, which can be fatal. Chloride maintains the balance of body fluids.
Electrolytes are clearly all very important, which is why Gatorade is so good at making you feel better after you’ve run a mile and were sweating out your electrolytes, or you’ve been sick and were vomiting up all your electrolytes.

Apocrine Sweat Glands

I haven’t given these glands very many words before because they aren’t found on your face, preferring only to hang out in all the spots that get hairy during middle school -- in your armpits and in your downstairs mixup. However, since your acid mantle is kind of all over your body, I feel like you guys deserve to know how these glands might affect it.
While these glands also look like spaghetti noodles, they’re a bit larger (so maybe more like worms?), and their noodly portion leads to a hair follicle rather than the skin’s surface. The apocrine sweat empties into the follicle, where it then empties out onto the surface.

Fig. 4, Apocrine Sweat Gland

(Couldn’t find a satisfactory microscope slide. Sorry!)

These glands use the same structural names as their cousins do -- the knotted bit is the secretory coil and the noodly bit is the sweat duct.

Fun Fact: While the apocrine glands we’re discussing today are only found in the hairy forests of your body’s landscape, some special, modified versions of these glands than can be found in other areas. There’s some in your nipples that can feed your babies, some in your eyelids that help with killing off bacteria, and some in your ears that make ear wax!

The sweat from these glands isn’t very effective at regulating your body temperature because the chemical composition is a little more lipid-y than eccrine sweat (and since these glands aren’t on your face, I won’t bother with a chemical breakdown here).
This sweat also as a more neutral pH, between 6 and 7.5, meaning your mantle isn’t very acidy in your pits. Between the lipidiness and the neutral pH, this sweat will forever leave you in dire need of some deodorant.
Sweat does not stink.
But bacteria, much like humans, enjoy munching on fat way more than they like munching on salty, pee-flavored water. They also thrive in more basic environments. The stink comes from the bacteria tootin’ up a storm while feasting on your armpit buffet. ^{Man, I am just full of beautiful imagery today.}

If your apocrine sweat doesn’t do any thermoregulating, then why are you cursed with these glands?!
Well, these glands are actually a throwback to your ancient ancestors, with the sweat functioning as a territorial marker (if it smells like you, it’s probably yours), as a warning signal (humans don’t get eaten when they smell gross, I guess), and as a pheromone (only baby-making humans smell like that ;D).
Due to the type of jobs that this sweat is meant for, it makes sense that these glands are activated by hormones rather than temperature. This means they don’t end up getting used until you’ve hit puberty and nature has deemed you old enough to need this kind of sweat. And because they are hormone-activated, this also means that these are the glands that are sweating whenever you are emotionally distraught. (Thanks, guys, for making the pits of my t-shirt wet during all of my high school book report presentations. You really know how to help out.)

Sebaceous Glands

You should know these guys pretty well by now. Not only have we discussed them before, but they are usually blamed as the source of your skincare woes. To be fair...they often deserve the blame. But with sebum carrying a pH between 4.5 and 5.5, these guys are often under-appreciated for their efforts in the fight against baddies.

Fig. 5, Sebaceous Gland

Fig. 6, Sebaceous Gland Microscope Slide

You might have also noticed in Fig. 6 that the follicle shown has two glands, but it's common for follicles to only have one gland hanging out nearby. They like being attached because, just like apocrine glands, they can deposit their sebum into the follicle, where it then flows out of the pore and onto the skin. The whole enchilada of a follicle paired with a sebaceous gland is known as a pilosebaceous unit.

Fun Fact: Some sebaceous glands do open up directly to the skin’s surface. These can be found as little bumps inside your cheeks, on your areolae, and near or on your nono-zone! (I would include pictures, but they’re all NSFW. D:)

The gland itself is an outgrowth of the follicle’s sheath, and it is filled with a special little cell called a sebocyte, which is the guy who actually makes the sebum.
You know by now how most cells go about delivering their products, right? They usually make a protein baby, and then poop it out of the cell membrane.
Glands with cells that deliver their junk in this manner are known as merocrine glands, and your eccrine sweat glands are an example of this type.

Fig. 7, Merocrine Gland Secretion

Some glands produce stuff that’s a little too thick to just poop out; you can think of them as needing some Metamucil. In order to deliver their junk, their cells need to wrap the secretion up in some of their cytosol and cell membrane before just severing the whole package. It sounds painful, but they manage to recuperate just fine.
Glands that specialize in this type of delivery are known as apocrine glands, and unsurprisingly enough, a great example of this type would be your apocrine sweat glands.

Fig. 8, Apocrine Gland Secretion

Well, our little sebocyte here likes to do things a bit differently. His junk is a lot thicker than the stuff other cells are making; thick enough that it makes him crazy constipated. In fact, he is so constipated that he will end up exploding in the process of trying to poop it all out. ^Gasp!
Glands whose cells will end up exploding in order to deliver junk are known as holocrine glands. Sebaceous glands are the only holocrine glands found on the human body.

Fig. 9, Holocrine Gland Secretion

Now that you know sebum is thick enough to make a cell explode, you might be wondering wtf is in this crap. Well, it’s even more lipidy than your apocrine sweat. In fact, its composition is 100% lipid, made up of triglycerides, free fatty acids, wax esters, squalene, cholesterol, and cholesterol esters.

Triglycerides

You might recognize this guy from our lesson on the hypodermis. This is the type of lipid that gets stored in your lipocytes, and the stuff you’re trying to get rid of when you start a new diet. This stuff composes the majority of your sebum, making up around 30-50% of it.
The official definition: A triglyceride is an ester of fatty acids and glycerol. In fact, they are sometimes referred to as esters of glycerol.

Okay, but what does this mean?
From “tri”, we can guess there is a triplet of some sort. This triplet just so happens to be three chains of fatty acids (more on these in the next section). Any fatty acid will do; some triglycerides have three of a kind, and some could have three totally different fatty acids.
The “glyceride” tells us that these fatty acids are all held together by a glycerol compound (also known as glycerin -- sound familiar?).

Fig. 10, Triglyceride Chemical Structure

In this picture, the red portion is our glycerol, and the black chains are our three fatty acids. The C’s in those chains are for carbon, and the lines drawn between them actually represent hydrogen molecules that are binding them together. (If you see a zig-zag without C’s, each point of the chain will almost always represent carbon, kind of like back in Fig. 3.)
So what exactly is an ester? It’s an organic compound (meaning, any chemical compound that contains carbon) made by replacing the hydrogen of an acid with a hydrocarbon group (a compound of hydrogen and carbon).
In triglycerides, our hydrocarbon group comes from the glycerol.

Fig. 11, Glycerol

Now, let’s attach our fatty acids to form an ester. We’ll use stearic acid (CH₃(CH₂)₁₆COOH) as all three of our fatty acids.

Fig. 12, Glyceryl Tristearate

Oh my...did you notice our stearic acids don’t end in -COOH like I had just said? They end in -COOCH! ^heh. This is because the hydrogen of our acids were replaced by the glycerol’s hydrocarbon group, a CH. By combining glycerol and three stearic acids, we’ve made glyceryl tristearate, a triglyceride!

Free Fatty Acids

Free fatty acids are exactly the same as the fatty acids we discussed above. They’re called “free” because these fatty acids aren’t being used to make any triglycerides, so they are unattached. They make up 15-30% of your sebum.
A fatty acid is an organic compound that contains a carboxyl group (that -COOH we mentioned earlier) and has a long chain of carbons and hydrogens trailing behind it, and the length of that chain can vary anywhere from 10 to 30 carbons (stearic acid had 18, by the way!).
Most of the fatty acids in your sebum tend to be unsaturated. This means that, somewhere along their chain, there is a spot where a carbon atom is bound directly to the next carbon in the chain, instead of every carbon being held together by hydrogen. To help you remember this, think of saturated fats as having a chain that’s fully saturated with hydrogen atoms.

Fig. 13, Saturated vs. Unsaturated

Saturated fats are solid at room temperature (e.g. butter), whereas unsaturated fats are liquid at room temperature (e.g. oil). This is why your sebum is oily rather than little beads of butter popping out of your pores. This also means you won’t be finding the saturated stearic acid in your sebum, but you will find sapienic acid, sebaleic acid, and linoleic acid, among others.

Sapienic acid is the predominant fatty acid in sebum. It gets its name from homo sapiens, because it is really difficult to find this fatty acid anywhere else in nature other than in human sebum. Some studies suggest that this stuff is the big hitter in killing off the bacteria responsible for acne, yet other studies suggest that people with acne have higher levels of sapienic acid than those without acne. In other words, science has yet to figure out what this crap actually does.
Sebaleic acid is pretty similar to sapienic acid, just with two extra carbons. It’s also similar in that it is only found in human sebum, and that it is depressingly understudied. :(
Linoleic acid is used by sebocytes to produce squalene, and the sebum of acne sufferers tends to have lower levels of linoleic acid and higher levels of squalene present. But we’ll get to that more in a minute. (Fun Fact: Linoleic acid isn’t naturally produced by the body, so it needs to come from your diet! You can find it in olive oil.)

The exact amount of each fatty acid, free or otherwise, that can be found in sebum will differ from person to person. But it’s worth noting that, while an acne-sufferer tends to produce more sebum than an acne-free person, if you were to take a sample the same amount of sebum from both types of people, the person with acne would actually have 53% fewer free fatty acids of any kind present.

Wax Esters

Wax esters make up 26-30% of your sebum. While not unique to humans, they are unique to sebum, as they aren’t produced anywhere else in the body.
Heyyy, weren’t we just talking about esters?! Why, yes!
So we know that triglycerides are an ester of fatty acids and glycerol. Well, wax esters are an ester of a fatty acid and a long-chain alcohol, with the alcohol’s chain being anywhere from 12 to 32 carbons long. Knowing how long fatty acids are, you can tell wax esters are really long.

Fig. 14, Wax Ester

Now, glycerol is an alcohol. But it doesn’t have a long chain, so triglycerides aren’t considered to also be wax esters. Also, they are triglycerides -- wax esters only have one fatty acid attached to an alcohol.

You might see “wax,” and start thinking of candles, Burt’s Bees, or Vaseline (which is actually a mix of wax and oil, by the way). While not all waxes are esters, they do all sort of function in the same waxy way. They seem to be even more water-resistant than oils and fats, and they are fantastic for lubricating and sealing in moisture. This is exactly what the wax esters in your sebum do -- they waterproof your skin, smooth it out, and try to lock in moisture.
The production of wax esters also seems to be related to helping sebocytes level up to the point where they are ready to do their exploding thing. While research has yet to uncover what exactly this relationship is, it has been shown that sebaceous glands tend to waste away when wax esters aren’t getting made properly. These guys do require a lot more studying in the future. (Isn’t it amazing how much we still don’t know about the human body here in the 21st century?)

Squalene

This one makes up 12-20% of your sebum, and it is yet another product that is kinda unique to sebum. (Fun Fact: Squalene gets its name from where it was first discovered -- in the liver of Squalidae, or dogfish sharks.)

When your body needs to produce a specific chemical, it’s a multi-stage process, with each stage involving a few steps. Think of it as baking a cake. The first stage requires filling a mixing bowl with dry ingredients. But to complete this stage, it has to go through the steps of measuring out, sifting, and adding the flour, baking powder, and salt.
To make cholesterol, the first stage is to make mevalonate. In order to complete this stage, your body needs to take the steps of measuring out three acetyl-CoA’s, then combining them. Stage two is to make isopentenyl pyrophosphate (don’t worry, you don’t need to remember that). And stage three is to make squalene.

Normally, the body uses squalene to carry out the fourth and final stage of producing cholesterol. But for some reason, your sebaceous glands are the only places in your body that prefer to halt production at stage three, leaving your sebum with way more squalene than cholesterol. While research has yet to come up with an answer as to why this happens, all we know is that it does, indeed, happen.
There is a theory, however, that the preference for squalene over cholesterol in sebum might be the evolutionary result of pollution. In other words, human sebaceous glands evolved to start making squalene in order to upgrade their skin protection in the face of an increasingly polluted environment.
Such an interesting theory makes it sound like squalene might do something really cool, right? Well, as it turns out, squalene is pretty cool.
See, when squalene is exposed to UV radiation, it begins to gobble up oxygen as an attempt to protect the skin from receiving the full force of the sun. If that doesn’t sound at all cool, don’t worry; we’ll be getting way more in depth about this in the next lesson.

Unfortunately, when squalene eats up oxygen, it results in squalene peroxide.
While squalene itself is not harmful to your skin, squalene peroxide definitely is. Your sebum will attempt to make up for the crappy side effects of squalene peroxide by additionally dumping a bunch of vitamin E onto your skin, but the good intentions don’t always cut it. Expect us to be digging into squalene peroxide a lot more in the acne section.

Cholesterol and Cholesterol Esters

Cholesterol and its esters make up only a measly 4.5% of your sebum. You can probably guess that the reason for this is because of the preference for squalene.
While cholesterol in cosmetics is used for its moisturizing properties, I honestly couldn’t find much information on the purpose of cholesterol in sebum. This lack of information leads me to believe this is because such an abnormally tiny amount of cholesterol might be viewed as sort of a byproduct of all the squalene production, rather than an “active ingredient,” so to speak. (But that’s just my take on it, so don’t quote that as a fact!)

That’s it for today, my dears! This lesson is already, like, five pages longer than I prefer them to be. ^{To be fair, I’m not exactly known for brevity. ;3;} I hope you’re ready to get slapped with even more säuremantel knowledge next time; my fingers are already itching to get started!

ѧѦ ѧ ︵͡︵ ̢ ̱ ̧̱ι̵̱̊ι̶̨̱ ̶̱ ︵ Ѧѧ ︵͡ ︵ ѧ Ѧ ̵̗̊o̵̖ ︵ ѦѦ ѧ ︵͡︵ ̢ ̱ ̧̱ι̵̱̊ι̶̨̱ ̶̱ ︵ Ѧѧ ︵͡ ︵ ѧ Ѧ ̵̗̊o̵̖ ︵ ѧѦ ѧ

Hello, everyone!
I hope you weren’t too disappointed by today’s lesson. I know the wait has been long, and I really wanted to squish all of the acid mantle stuff into one lesson, but my character count has forced me to split this subject in two. I’m worried you’re all getting pretty sick of these super science-heavy lessons, since it might not seem immediately clear how any of this info is relevant to managing a skincare issue.
But hopefully you guys will bear with me and just trust that this will all make sense in the end! I really appreciate all of you for sticking around and reading my walls of science text. ♡ Thank you for reading, and leave any questions below. :)

Please Note:
There was a lot of info I left out of the section on lactate, like the fact that triglycerides can also be used in anaerobic respiration, or that lactate has nothing to do with post-workout muscle aches. I also left out a lot of chemistry-related info regarding saturated/unsaturated fats and wax esters.
I did this because I figured these tangents would take us unnecessarily off topic, but if you would like to know more about rest-of-the-body biology or chemistry, feel free to ask about it in the comments or send me an email if you’re on the mailing list. Because, as much as I would enjoy going more in depth on human body biology in a lesson, that’s not really a topic relevant to this subreddit, haha.

conjugate base chemistry definition video

A conjugate base, in an acid-base reaction, is the product that results when acid is deprotonated. Conjugate Base Explained: A conjugate base is, therefore, an acid with a hydrogen atom removed from it. A strong conjugate base results from a weak acid. A weak conjugate base results from strong acid. Examples – Leave a Reply Cancel reply. Save my name, email, and website in this browser for ... l'hybridation peut avoir un effet très importants sur la stabilité et la stabilisation de la base regardons la molécule des paris illicites si je regarde ce carbone ces carbone cer je sais qui il a vidé quand sp 3 en cas d'hybridation ses perspectives si jamais il se peut que le soutenir ainsi par une balle je vais voir les électrons de cette saison qui vont être rabattus sur ce qu'un ... In this lesson, you'll learn about conjugate bases in chemistry and where they come from. You'll also learn about their relationship to acids and see how acid-base reactions work. Conjugate Bases ... The Bronsted-Lowry acid-base theory includes the concepts of conjugate acids and conjugate bases. When an acid dissociates into its ions in water, it loses a hydrogen ion. The species that is formed is the acid's conjugate base. A more general definition is that a conjugate base is the base member, X-, of a pair of compounds that transform into each other by gaining or losing a proton. A buffer is a solution containing either a weak acid and its salt or a weak base and its salt, which is resistant to changes in pH. In other words, a buffer is an aqueous solution of either a weak acid and its conjugate base or a weak base and its conjugate acid. A buffer may also be called a pH buffer, hydrogen ion buffer, or buffer solution. A conjugate base is the name given to the species that remains after the acid has donated its proton. The conjugate base can accept a proton. Conjugate Acid Example . When the base ammonia reacts with water, the ammonium cation is the conjugate acid that forms: NH 3 (g) + H 2 O(l) → NH + 4 (aq) + OH − (aq) Source . Zumdahl, Stephen S., Zumdahl, Susan A. (2007). Chemistry. Houghton Mifflin ... Conjugate acid base pair or protonic definition of acids and bases independently proposed by Bronsted and Lowery in 1923 for learning chemistry or chemical science. According to this definition, an acid is any hydrogen atom containing material (molecule or ion) that can release a proton or hydrogen ion to any other substances, whereas a base is any substances (molecules or ion) that can accept ... 8.1.3 Deduce the formula of the conjugate acid/base of any Brønsted-Lowry base/acid IB Chemistry SL - YouTube; The conjugate base is the other product, which has had a proton removed. Brønsted Acids and Bases. The conjugate base is the ion or molecule that remains after the acid has donated its proton, and the conjugate acid is the species created after the base accepts the proton. Water is ... Other articles where Conjugate acid-base pair is discussed: acid–base reaction: The Brønsted–Lowry definition: …and B together are a conjugate acid–base pair. In such a pair A must obviously have one more positive charge (or one less negative charge) than B, but there is no other restriction on the sign or magnitude of the charges. Définition du conjugué en chimie. Thoughtco Jun 05, 2020 (2) Dans le Théorie de Bronsted-Lowry des acides et des bases, le terme conjugué désigne un acide et une base qui diffèrent l'un de l'autre par un proton. Lorsqu'un acide et une base réagissent, l'acide forme sa base conjuguée tandis que la base forme son acide conjugué: La flèche de réaction pointe à la fois vers la gauche ...

Definition of conjugate base in Chemistry, Microbiology.

conjugate base chemistry definition

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Ions, acids, compounds

Acids and bases

ph and solubility

Tips and advice for current/future IB students

AP Bio Guide (Units 8 in comments)

1) Chemistry of Life

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Calculations

Labs

2) Cell Structure & Function

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Calculations

Labs

Relevant Experiments

3) Cellular Energetics

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Calculations

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4) Cell Communication & Cell Cycle

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5) Heredity

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6) Gene Expression and Regulation

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7) Natural Selection

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Part I: Destiny's Main Logo is the Y-Goblet & How it's chemical cocktails reveal everything (The OXA Machine + Way Way More) (Ultra Extreme Deep Lore)

Skin Basics 1.6.1 - The Acid Mantle - Sweat and Sebum Skin Basics 1.6.1 - The Acid Mantle - Sweat and Sebum

Disclaimer

Lesson 1.6.1: The Acid Mantle

What Is The Acid Mantle?

Eccrine Sweat Glands

Urea

Lactate

Sodium, Chloride, and Potassium

Apocrine Sweat Glands

Sebaceous Glands

Triglycerides

Free Fatty Acids

Wax Esters

Squalene

Cholesterol and Cholesterol Esters

conjugate base chemistry definition video

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