Two Questions about Biochemistry

[ieatshrimp24]

1) About how much detail should we study the biomolecules for the MCAT? For example, do we need to know the amino acid codons? Do we need to memorize the different ways to diagram glucose, fructose, ribose, etc.? I'm not worried at all about knowing the structures of amino acids since I already know them but I'm wondering about the other details.

2) Is Khan Academy for biochemistry a legit/representative source for the MCAT biochemistry topics? I already have TPR Biology review and there's like nothing on biochemistry. Plus, I don't want to buy Kaplan Biochemistry book since Khan Academy has A LOT of material. I'm just wondering if all that material in Khan Academy does not go to waste, meaning is it good enough to study?

Just wanna say that I think biochemistry is a lot of fun and I hope my MCAT score reflects that. Thanks!

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[El-Rami]

1) Know them fairly well inasmuch as the broad concepts such as thermodynamics of protein folding and cooperativity. You do not need to study the codon chart; it should be provided if even needed to answer a question. For carbohydrates, I would know structures, although this is my own opinion.

2) I don't know about Khan Academy, but I do like the Kaplan Biochemistry book. It explains the basic concepts fairly well and deals with metabolic pathways.

 

[ZDMaestro]

1. You need to know the start and stop codons. AUG is start (methionine), UAG, UAA, UGA are stop. You need to know how this relates to the tRNA (it would be the complement). I would make sure you know how to go back and forth between Fischer and Haworth projections. If it were me, I'd be sure I had Beta-D-glucose memorized at minimum. Understand how this changes with varying anomers, and the difference between beta and alpha. I would probably also know fructose and ribose if I were you. The different carbohydrates are easy to memorize if you just memorize glucose and then relate all of the others to glucose from a Fischer projection perspective (e.g. galactose is a C4 epimer of glucose, etc.).

In addition to knowing the amino acids (I know you said wasn't a problem), you also need to be able to generally estimate each pKa (not difficult—the terminals are all about the same, and then the chains can be estimated by whichever functional group it is; be aware of the ones that are unusual, such as histidine [I think it has one of its pKas around 6 or something (don't nerd rage if I'm wrong though)]). You'll need to be able to predict the charge/structure of each amino acid at any given pH, and also the same for a given chain of amino acids, including some chain's pI value. You will almost certainly see at least one question that requires these skills. I'd say you'd probably see two.

2. I think Khan is good, but I'd skip it unless you need it for clarity. I much prefer books when learning a huge amount of material like this. If it were just one topic, or even just one subject, I'd say use videos. But when there's such a dense amount of information, I think it's best to have a book (in addition to video sources). I've heard of people using only Khan (on SDN), but I just need something physical sometimes so that I can mentally organize and contextualize information.

Also, refer to this video on media learning. Don't watch a video and be fooled that you "know" it just because you understood the video when you saw it...


As a side note, memorize all things psychology/sociology. The best way to describe it as a university college exam. Memorize facts, and you can probably get 75-80th percentile without reading the passages. It's so dumb...

 

[ZDMaestro]

Disclaimer: I love Khan and what he's done. I don't mean to throw hate at Khan by sharing that video; I just think its in our best interests to be critical of how we are learning and its effectiveness (which is unrelated to how effective we emotionally think it is)...

 

[ieatshrimp24]

That was a great video about why Khan may or may not work. The guy did say however that Khan Academy may be good for a review and not for learning something brand new. I've already taken two biochemistry courses and I'm pretty sure they've covered everything that is needed to know on the MCAT. I just don't wanna pay up more money for the Kaplan Biochemistry book if it reads like a textbook and is not very helpful.

Anybody with other thoughts on biochemistry on Khan and Kaplan?