Hello! I would like to share some of my experiences with taking biochemistry. This has been one of my favorite and most rewarding courses and was an integral part of my undergraduate experience. For some context, I have taken undergraduate biochemistry and first year graduate biochemistry and performed in the top 10% of the class, 132 on bb and cp section on the MCAT. I'm not by any means an expert however, so feel free to disagree with what I say.
First, there are some general chemistry topics that are extremely important for both organic chemistry and biochemistry. Those include the theories of bonding (Valence bond theory, Molecular orbital theory, hybridization), intermolecular forces, acid-base equilibria, and thermodynamics/kinetics. I would say ~80% of biochemistry/orgo can be reasoned to these basics.
Certain organic chemistry reactions will appear many times in biochemistry. In order of importance, you need to know 1) Mechanisms and reactions associated with nucleophilic acyl substitution, associated carbonyl chemistry, enolate chemistry. The bond forming reactions in biochemistry all involve the alpha carbon so it is extremely high yield to understand the complete mechanism of the reaction and the various perturbations such as changing pH, polarizability, etc. You will see a lot of oxygen, carbon, and nitrogen nucleophiles, so it is valuable to review C-C bond formation reactions (Claisen, Aldol, Michael addition), C-N bond formation reactions (imine, enamine), and the C-O (acetals, hemiacetals). These appear in the biomolecules you will see; C-N bond formation in peptide bond formation, acetal and hemiacetal formation in sugar reactions, C-C in fatty acid and polyketide synthesis and prenylation (not needed for premed or undergrad biochem but this is really cool stuff! It’s how stuff like erythromycin are produced). Protecting groups such as silanes, carbamates, etc for macromolecule synthesis in biochem II.
There is a heavy emphasis on understanding biomolecules from Biology 1. You should know structures of DNA/RNA/amino acids/carbohydrates/fatty acids. But don’t memorize all of the structures and names before you take the class! It will be much easier knowing what is relevant and besides, only the functional groups involved in reactions are the important parts. It’s more valuable to know the kinds of reactions and mechanisms they undergo than the structures themselves, which you can generally look up online or in a reference text. EXCEPTION: Amino acids. Know them all like you know the common elements of the periodic table. PKA’s nice but don’t bother memorizing to the last decimal point. Also memorize the range bc I guarantee you in real situations, the environment highly highly affects the acidity (covered in biochem II, really cool stuff!). This way you aren’t set on a single value and can consider factors like hydrophobicity and proximity to other groups to identify residues.
Michaelis-Menten Kinetics and other models: This is kinetics from chem 1 + some algebra. Don’t be afraid of these. Review the derivation of reaction rates using the steady state approximation and that’s how the values are derived. In biochem II, kinetic isotope effect (including solvent KIE, deuterium, tritium, etc), Arrhenius type models for transition states, experimental elucidation of enzyme reaction mechanisms, etc really explain how models taught in biochem I are developed. (briefly) brushed a bit over Xtal but very very briefly. Cryo-em and discussion of how those cool images in books like Voet are made. Assembly macromolecular synthesis like PKS and NRPS. Discussion into protein folding/protein degradation, mechanisms of translation. All of these rely on concepts from physical organic chem or thermos/pchem so be aware of those before taking biochem II. (Biochem II classes vary from university to university so your mileage may vary.
How do you succeed in class? Attend lectures. Do your problem sets. Always ask questions. Many many times I had to swallow my pride and ask about clarification on things that everyone seemed to nod their head to, but not once did I regret it. Chances are if you did your work and are prepared but still don’t understand something, that thing is difficult for others too. The material I used to prepare were the textbook and the lecture notes from class. It’s not worth to go memorize the textbook because there is a lot of trivia that isn’t that relevant to the big picture and actually obscures what’s important. Examples: when learning the glycolysis pathway, don’t bother with enzyme names/molecular names (those come later), but focus on the steps each enzyme does to the substrate. It’s okay to know what the molecules are but not know what they’re called, but it’s NOT okay to memorize the pathway names and enzymes and know nothing about what the reactions do to the previous metabolite. Understand why things are regulated; I think voet has a section about thermodynamic gate vs quick equilibrium which I found more relevant than the minutiae of the pathways themselves.
I hope you enjoy biochemistry!!! Sorry about the long post
EDIT: Typos and minor fixes
