For your own sake, just don't take any of those classes. Take something easy instead, and give yourself some free time to chill and do some serious lounging around before you start med school. Yeah, you can take some hard class that might force you to think a little bit more about enzymes and reactions and cell processes and crap, but in reality, its not going to even really touch on what's important for you to need to know in medical school, and it's probably a waste of your time. Like the person a few posts above said, you don't usually have to memorize exact structures and pathways for everything you learn. Also, unlike in your undergrad class, things will actually be less theoretical and focus more about how it relates to a certain disease process or clinical situation, and questions on tests are all cased-based. There are of course a few exceptions about memorizing details of certain things. At one time or another you're going to have memorize glycolysis, the pentose shunt, adrenal steroid synthesis, you know, silly things like that which will be important
Personally, I never took either biochem or cell bio in college and did very well in first year med school. Biochemistry and cell bio really are the basis for physiology, path, and pharmacology, and in third year i find myself going back to those basics every day when thinking clinically. While they're important though, if I could go back and take them in college, i wouldn't and I'm glad i didn't. If you wish to stress yourself out and take one of these two classes, nooone can stop you, and in that case I vote for cell bio
