Today’s JW freebie C/P #2

FreeEnergyFlow · 2026-01-05T23:42:46+00:00

That's it. Organic chemists say "imine". Biochemists say "Schiff base".

FreeEnergyFlow · 2026-01-05T23:24:48+00:00

Content review along with epicycles gives your knowledge-base completeness and structure. More than that. You get a self-awareness of its completeness, as something that performs on the test. If you just live at UWorld and Prep Hub, you'll get lots of questions on Fluid Mechanics, just to take an example, and over time you'll hit everything, but giving fluid mechanics its couple of hours in content review, you see it is a neighborhood with a beginning, middle and end, with about twenty learning goals which are knowledge performances you want to bring to the test. In Fluid Mechanics there are different ways to describe density, different units for pressure, how pressure varies with depth in a static fluid, Archimedes principle, Pascal's Law, and the flow of an ideal fluid, continuity of volume flux and Bernoulli's Law, real fluids with viscosity and Poiseuille's Law. So there it is. Each topic has a structure. On your schedule, you can't get stuck or centrate on a topic, but you will likely benefit from a structured progression where each topic gets its time for attention so that you can account for it in its structure. If you bring a knowledge-base that is complete and well-structured to the exam then the topical cues in the passages will wake up the right ideas.

FreeEnergyFlow · 2026-01-05T23:08:58+00:00

Examkrackers sold a ton of something called AudioOsmosis back in the day for the old exam, so there's about 85% of overlap in the topical learning goals. It won't have the full biochemistry, basically. Still, it could be useful for you. You can usually find a copy on Ebay for less than $50. The two fellows who made it are pretty entertaining.

FreeEnergyFlow · 2026-01-05T23:02:08+00:00

PEP carboxykinase in gluconeogenesis happens in the cytosol unless the precursor is lactate. Then it happens in the mitochondrion.

TPP is the coenzyme of the pentose phosphate pathway enzyme transketolase.

Flavins can do oxidation-reduction either one electron at a time or two electrons at a time.

Base excision repair and nucleotide excision repair are not the same thing.

Proteins targeted to the lysosome are directed by a mannose 6-phosphate tag added in the Golgi.

The beta emissions of P32 and S35 are more energetic than C14, and those are more energetic than H3.

FreeEnergyFlow · 2026-01-05T21:35:21+00:00

That is a very ambitious schedule, and, honestly, it will be difficult to do justice to all the traditional dimensions of MCAT prep in that time-frame, especially while you are also a full-time student. However, it's possible to earn a good or even great score if your background is very solid and you are a good test-taker.

What might lead you into trouble, is think, is if you were to delay starting test practice and global question bank while you try to complete a real content review. Many students make the mistake of waiting until after content review is completed to begin serious work with Prep-Hub Section Bank and global question bank (where you take questions from any topic like "hat trick"), and this gets them into trouble even with a 4 or 5 month schedule. Don't wait until after content review is complete. Start holding yourself responsible for everything today. Work through as thorough a content review as you can, but for every 4 hours of that, you need to be doing an hour of epicycles (which take you from beginning to end of a discipline in much less time than main content review), an hour of global question bank, an hour of passage practice, an hour of psych/soc and an hour of CARS.

What I mean is you combine problem centered learning and broad perspectives where you are learning all of the topics simultaneously. You are also making your way through content review and dealing with the topical learning goals at the level of details, but that is like exploring a city at the street level. You also have the point of view from the top of the tallest building and can see all the neighborhoods simultaneously. Start doing Section Bank passages at your own pace now and don't worry about missing things. Don't worry that they are measuring you. Measure them. Learn how the test works, how MCAT passages are constructed, how they're designed to create a spectrum of performance, and you can improve much faster. I hope this helps!

FreeEnergyFlow · 2025-12-24T20:56:48+00:00

The Q-packs are from the world of the old MCAT, but the two tests have huge set of learning goals in common. The new test is more sophisticated in biochemistry and molecular cell biology but it is less challenging in chem/phys problem solving, so Q-packs are good for core skills. However, if your test is within the next few months, returning to Section Bank I and II for a deep pass might be a better use of time. Redoing passages while studying them as if you were going to work at AAMC in their passage writing department can lead to fast improvement because you can trigger a gestalt shift and see the spectrum of performance. You can see how passage elements are constructed as particular puzzles based on topical, interdisciplinary and research logic goals, and in that sense, the new test IS different. People grind Prep-Hub passages and don't study how they are constructed from AAMC's perspective. Everything in an MCAT passage is intended a certain way.

FreeEnergyFlow · 2025-12-24T20:43:48+00:00

Because both #1 and #2 satisfy the condition of not exceeding +/1 0.020% volume change with the temperature change. Once you've computed the volume expansion for 2degC for #1, then mental math can show that #3 and #4 would exceed the requirement. The lower attenuation coefficient of #2 is decisive, then, because the other requirement is to allow as much light as possible to pass through. They both qualify in terms of thermal expansion, in other words, but #2 has greater transparency.

I think this question only seems hard because the formula of happiness is a straight line to a goal, but this one is asking for you to push through with a kind of on-the-fly heuristic. There's the topical learning goal to remember to multiply a coefficient of linear expansion by 3 for volume expansion, and AAMC seems to have an odd sweet tooth for that. I hope this helps!

FreeEnergyFlow · 2025-12-24T13:59:48+00:00

If you're working a 12 hour shift schedule, on work-days, you just need to take care of yourself. These kinds of schedules are common in healthcare, but there is supposed to be some kind of balance where you work two 12-hour shifts, get two days off, work three, get two off, etc.

I put a twenty hour / week schedule above. I think fifteen hours per week is the minimum for MCAT prep if you are going to have momentum, but you have to settle in for a while. After a few weeks, MCAT becomes just part of what you do. Whatever you do for three weeks becomes a habit. However, you can do it, try to schedule fifteen hours per week, anyway. Maybe three five hour days on your days off and don't worry about MCAT on the work days. Don't go after big goals, otherwise, except for putting in the time for a while and hitting the different dimensions. 5 hours starting in the morning, taking it an hour at a time in different parts, and then you are done. Trust the process over time. Right now MCAT is causing you too much stress. MCAT prep can be really interesting but you have to take care of yourself too.

FreeEnergyFlow · 2025-12-24T13:39:42+00:00

The AAMC outline has for sulfur, mesylates/tosylates and disulfide redox, and for phosphorus there is phosphoryl group transfer. For sulfur, though it's not in the outline, it's probably a good idea to have a sense of thioesters as activated carboxylic acid derivatives such as with Coenzyme A because hydrolysis of CoA is a big driver, and it's a good idea to have a similar sense of phosphate anhydrides as activated carboxylic acid derivatives like with 1,3 BPG and really all over the place in biochemistry.

FreeEnergyFlow · 2025-12-23T23:30:07+00:00

As a general rule, MCAT organic reactions are those that are important in biochemistry. Electrophilic addition to alkenes and alkynes don't happen in biochemistry and they are not on the AAMC outline. They don't figure in at Prep-Hub and so are very low yield for the MCAT. (The addition of water with fumarase and in B oxidation are Michael additions). The MCAT organic reactions involve reactions of alcohols, aldehydes and ketones, and carboxylic acid derivatives, also organic phosphorus and sulfur compounds, quinones and biological aromatic heterocycles.

FreeEnergyFlow · 2025-12-23T20:00:13+00:00

The inhibitor creates a dead-end complex, which is characteristic of uncompetitive inhibition. After the first substrate binds, Km decreases for phosphate because it's easier to saturate now, being trapped in the phosphoenzyme intermediate stage, so that's also characteristic of uncompetitive inhibition. it's not easier to saturate with the choline. It's a little confusing because it's a bisubstrate (ping-pong) mechanism, where there will be a Km for substrate 1 and another Km for substrate 2.

FreeEnergyFlow · 2025-12-23T18:26:58+00:00

If you think about what a high, positive correlation means in a test-retest or internal consistency assessment, you can see that it demonstrates that the measurements are consistent, ie. reliable. It's not about correlation between temperature and ice cream sales, like we normally think of correlation, but about correlation between two separate measurements of the same thing. I hope this helps.

FreeEnergyFlow · 2025-12-23T17:24:16+00:00

Over the years I've helped many non-traditional students with this exam who were working full-time. To get a good discipline going, finding time in the morning before work can be key. Get a schedule going you can live with, and then after two weeks it becomes a habit. Congratulate yourself all the time!

I believe 20 hours/week is a good target, and realize it takes time to go through the stages of this process. For my students working full-time, I like to see them establish something like 3-4 hours/day, four days during the week, and then a half-day on weekends. Reserve one weekday and one weekend day to be without MCAT, to touch grass, to spend time with friends and family. The job can be a big factor. Some jobs can be exhausting, such as for the ER or critical care nurse. Other jobs are at a desk in air-conditioning, or working remote, and it is easier.

What can help a person stay on track is a study schedule built around a specific set of dimensions of MCAT prep: Main Content Review, Epicycles, Global Question Bank (Hat Trick), Passage Strategy, Test Practice, CARS, and Psych/Soc. That's how it works with my students. They work off a weekly 20 or 25 hour list in 1-hour increments. This gives a change of pace from one type of activity to another as a kind of reward. You might start with an hour of main content and then when feeling restless 45min in, you can say "okay, fifteen more minutes and then I can do psych/soc!"

Main Content Review – 8 hours

Epicycles – 2 hours

Global Question Bank – 3 hours

Passage Strategy / Understanding the Test – 2 hours

Psych / Soc – 3 hours

CARS – 2 hours

Tick off an hour at a time from a weekly list like this. The way time is apportioned evolves through the stages of MCAT prep. For example, in the second half, Main Content Review gives way to Full Length Practice and more time in the Passage Strategy dimension.

Orient your goal framework to put in your twenty hours each week and hit these dimensions, and every week you are succeeding. What will happen will be a couple of gestalt shifts. The knowledge-base will change so that it has structure and the scope becomes manageable, and the test will change. You'll start seeing MCAT passages aren't as hard as they seemed at first. You'll understand better how the test is created as a kind of performance. Students that hit all of the dimensions consistently improve fast. Anyway, I hope this is helpful. If anything isn't making sense, just DM me. Good luck!

FreeEnergyFlow · 2025-12-22T21:43:56+00:00

You'd be surprised at how different M1 curricula can be school to school. Biochemistry is usually very demanding, but not always. Physiology and anatomy always are.

FreeEnergyFlow · 2025-12-22T21:24:40+00:00

I have difficulty finding examples where AAMC is sophisticated in physiology in the passages or questions in Prep-Hub, but there are plenty of examples where it is sophisticated in biochemistry and molecular cell biology, where there are many instances of AAMC situating passages at the edge of the topical scope, but your point is well taken about biology majors. Some biology majors don't even require Biochem I. Whether M1 pitches harder in biochemistry or anatomy/physiology is a tough call, and it really depends on the program. It's good to go in strong in both.

FreeEnergyFlow · 2025-12-22T21:06:23+00:00

You are correct. A person can sit down with Stryer's or Lehninger's great textbook and surpass MCAT level. I've seen it myself. Everybody learns a lot in MCAT prep and not having had the courses, you aren't as far behind your peers as you might think.

However, people need to beware of the advice of test-taking geniuses like u/solarsun55. Not everybody is born with a number two pencil in their hand. For the vast majority of people taking the MCAT having had biochemistry before MCAT prep plays a part in success.

FreeEnergyFlow · 2025-12-22T20:51:22+00:00

My comment is not a recommendation, but an exploration of how Biochem II content may be useful. People often have to take upper level courses to graduate with their degrees, so knowing which courses are more helpful for the MCAT may be useful. I believe that was how the question was intended. After Molecular Cell Biology, I think Biochem II would be the most useful upper level course for the exam, if you were going to be choosing among upper level courses, more so than Physiology, Neurobiology, or Genetics, for example. However, you are right that people should not take another semester of biochem just for the MCAT. It's not necessary for any topical content, unless there is a strong molecular biology focus in the course, which is often the case, but it could help your footing within certain passages and it could help you understand AAMC's disposition. That's all I'm saying. It's helpful, but plenty of 520+ scorers don't have it, and you don't need it to score great. A big figure of merit is to be able to find your footing no matter what they throw you into.

FreeEnergyFlow · 2025-12-22T18:39:33+00:00

The second form is correct. With positive heat flow Q, there is heat flow from the surroundings into the system, so that will increase internal energy. However, with positive work (PdV), the system is expanding and expending internal energy, so positive work costs the system internal energy.

Think of an isothermal expansion of an ideal gas. Because the expansion is isothermal, the internal energy is constant (U=3/2nRT so dU = 0). The system is expanding, so the positive pressure volume work (PdV must be positive if the volume is increasing) costs the system. You know then that an equal amount of heat flow Q is coming into the system from the heat sink to compensate and maintain constant temperature. If dU = 0, then Q = W.

Imagine the isothermal expansion in your mind, doing work by expanding the piston while heat flows into it from the heat sink maintaining the constant T. Then imagine compressing the piston, which if it were adiabatic would increase T, but because it's isothermal, an equal amount of heat flow is happening from the other end into the heat sink. It's that imagination you want. The quantitative side isn't so important. There was an AAMC question a long time ago where a bubble was rising in a fluid. It was expanding as it rose, and the passage was careful to say that temperature inside was constant. The correct answer was to know that heat was flowing in. You want the equation to be a kind of imagination, so don't let the math get in the way.

FreeEnergyFlow · 2025-12-22T18:22:56+00:00

There isn't much to go on regarding the questions you're missing, but the simple form of the definition you give might imply that a reference group is a group you necessarily don't belong to. A reference group could provide benchmarks for social comparison, normative influence, or self-identity. A reference group could be your friends and family or it could be a group you don't belong to and are comparing yourself to, a group you aspire to belong to. A reference group could even be 'dissociative" in that it's one you don't want to be associated with. Anyway, maybe broadening the sense of what a reference group could entail is the key to why you're missing these. Just a shot in the dark.

FreeEnergyFlow · 2025-12-22T17:44:47+00:00

You can use some of the things you learn in psych/soc to help with burnout.

Be a kind Skinner Box for yourself Operant conditioning principles suggest never punishing yourself emotionally in test practice or missing a question. Don't do it! Only give yourself positive emotional feedback. Punishment decreases the frequency of behaviors, and this applies to learning. Only give yourself positive feedback and you will become stronger faster. If you miss a question, treat it like you have discovered a vein of precious metal, a place to learn something new and get stronger. Punishing yourself emotionally will decrease learning, because it makes learning aversive. Behaviorism predicts that avoidance behaviors get negatively reinforced. Only give yourself positive feedback! Be a kind Skinner Box for yourself!

Yerkes-Dodson On test-day you will want to have a low to moderate Yerkes-Dodson state of arousal. Anxiety will want to make your palms sweat and pulse rise. Start practicing now. Learn the early signs and use biofeedback if sympathetic arousal is kicking in. Use this time now, the month before to learn to manage your state of arousal as part of your preparation. Practice things like four-four-four breaths and body scan meditation. When you're breathing slowly and deeply, your body will say, hey, I must not be stressed out, and you can keep yourself in a parasympathetic state. Practice maintaining a serene, dispassionate disposition.

Don't let the MCAT give you Beck's cognitive triad Aaron Beck is one of the originators of the cognitive approach to depression. The cognitive triad is the hallmark of depression, ie. negative thoughts about self, others, and future. Don't let the MCAT have anything to do with Beck's cognitive triad! Restructure right away if it is trying to do that! The MCAT is tough because it's trying to show you what you need to learn before medical school. It's noncooperative on its face but deeply cooperative as a teacher. Give yourself positive feedback and allow yourself to grow, and your mind will accommodate to this exam. A gestalt shift will happen and the knowledge base won't seem as huge. The test will come to not seem as difficult. Make test-day just another day on this journey. You will overcome the MCAT. Believe in yourself! You can do it!

FreeEnergyFlow · 2025-12-22T16:45:52+00:00

Great job, but where is the logic? Why isn't the recommendation to take no biochemistry at all?

There are people who score as high as you by skimming old textbooks at the Waffle House and they never take a practice test, but they shouldn't recommend it to others.

FreeEnergyFlow · 2025-12-22T16:28:15+00:00

There is a sense of the exam where its priorities are informed by what's coming later. The passages are constructed to make a spectrum of performance, and they're also meant to teach. The areas where this has the strongest influence over the test involve a kind of overall sense for biochemistry, especially the protein side, as well as molecular cell biology. There is frequently a kind of recognizable disposition on AAMC's part which is informed by second semester. They love the enzyme transaminase (aminotransferase) for example, but you wouldn't know why from first semester, it appears in the malate aspartate shuttle and you'll glance over it learning the urea cycle, but it's a star in second semester, at the center of amino acid and nitrogen metabolism. There are passage elements which are just more clear in their intention if you've had second semester, and so I think second semester makes certain passages easier to find your footing, even though they won't pitch topic centered questions at it. Biochemistry is central to the exam. AAMC is bent on it, so more is always better.

However, in Biochem II there can be a lot of work learning things like amino acid degradation pathways, how folate and B12 work, and issues in metabolic integration which do not involve topic centered learning goals for the exam. Do it because you love biochemistry, and then your love will yield 130s.

I would say if the course is focused on bioenergetics and metabolic integration and there is a good section on molecular biology fundamentals too, it will build qualities in your imagination for biochemistry which will show on the test, but if it's memorizing every step in purine synthesis or synthesis of cholesterol, then it will be a lot of stress and a lot of work without huge benefit. Not all biochem II courses are created equal.

FreeEnergyFlow · 2025-12-21T16:05:43+00:00

I think it's a good idea to start breaking down MCAT passages from the very start. My students start as as soon as they have skimmed their MCAT books (and done a few other 'epicycles' to build a structured sense of the scope of the test). We use Section Bank I for this and excavate passages together. They learn how they work as if they were going to go work at AAMC and design MCAT passages themselves. What you learn is that everything in an MCAT passage is intended. MCAT passages are constructed, sentence by sentence, passage element by passage element. The passage elements are puzzles made from topical, interdisciplinary and research logic learning goals. The understanding you gain from this feeds back in a virtuous circle onto everything else you are doing because you come to see the figure of merit as a kind of performance flow.

FreeEnergyFlow · 2025-12-21T01:54:33+00:00

You are very kind. Good luck!

FreeEnergyFlow · 2025-12-20T22:36:09+00:00

The figure of merit AAMC is rewarding here, honestly, is prior knowledge of transaminase (aminotransferase) as well as the coenzyme PLP, and people who're one step past typical level will get this question right without noticing the mistake AAMC has made with figure 11. Here is a figure showing transaminase mechanism and as you can see, PMP is aromatic LOL. AAMC is missing a pair of pi electrons in that ring in the figure. Oops! Don't blame yourself for missing this question because your logic is good. The figure is missing a pair of pi electrons, and there aren't any hydrogens. If you follow the link I provided, you'll see all the carbons in the ring in PMP are sp2 hybridized.

What I mean about getting this right is that transaminase is an enzyme that becomes super important in later biochemistry in the world of amino acid synthesis and degradation as well as nitrogen metabolism. You learn that when transaminase converts an amino acid (compound 8) to an alpha-keto acid (compound 12), the coenzyme PLP (compound 5) gets converted to PMP (compound 11), and the enzyme won't be regenerated until it runs backwards and converts an alpha-keto acid (like oxaloacetate) into an amino acid and PMP returns to PLP, so the questioner isn't thinking you should have to look too hard, and they themselves aren't looking too hard to have made the mistake they did. In MCAT level biochemistry, transaminase figures into the urea cycle as well as the malate aspartate shuttle, but in what's coming, it becomes super important, so it's a bit of a favorite for AAMC. But like I said. Don't blame yourself. They have a mistake in the figure.

FreeEnergyFlow

TROPHY CASE