Question

So, I'm super terrified because I have a biochem final and I have to memorize so many pathways w/ their chemical structures and their enzymes. WHO HERE HAS PREVIOUSLY EXPERIENCED THIS?

Answer 1

I used the following method, i memorized firstly where the diffrent pathways integrate and interacts. Then i memorized the diffrent pathways, afterwards i applied the diffrent processes which happeneds between diffrent steps (e.g Decarboxylation, Oxidase, Reductase etc) Then i memorized the Allosteric regulations of each pathways. Aswell as other autoregulations enzymes.

This might not work for you, you'd just have to find the best way to structurize it in your head so you can visualize it when you think about it.

Answer 2

Oh yes, everyone experiences this.

1. I start by thinking about what process each pathway actually does, what its purpose is and why it is important to the cell.

2. Into that framework, I look at how each step in the process contributes to it. There are patterns in the energetic stability of, for example, the glycolytic intermediates which make it easier to remember which one belongs where in the process and why. The enzymes are named for their reactions, so remembering that phosphoenolpyruvate (PEP) kinase phosphorylates PEP is easy.

A note: I found that much easier when I started thinking about the actual 3D structures of the intermediates, not the 2D sketches on a piece of paper. I understand that the 3D structures are not typically taught and students do not have ready access to that info (I think they should) - I just note that when I looked that up, it took most of the pain out of intro biochem.

3. Look for similar overall patterns (sometimes called reciprocal regulation) in regulatory networks. In general, the same overall regulatory processes like phosphorylation have opposite effects on proteins which function in opposite pathways. Like phosphorylation and dephosphorylation in glycogen metabolism.

4. Exuras is right: start at the points where pathways interact or have big energetic differences between product and substrate. These are the important ones, essentially where a cell commits a reactant to a certain metabolic pathway. The enzymes will almost always be controlled by covalent modifications. The others are just links in the chain and will, in general, be regulated just by concentrations of product and substrate.

Good luck!