While those classes don't give alot of credit, be prepare to live in the library.
I found microbio the most enjoyable out of all the bio classes I had to take. It's pure memorization (naming, classification, identification, and tests/treatments). Find a professor that makes it enjoyable and links what you learn in lab with what you learn in lecture.
Physio is a bit more memory intensive, and has some application problems associated with it (urea, 02/c02, diffusion gradients, ca/na/k pumps and channels, glucose/insulin pathways, and role cns/pns plays). I hated the physio lab. Lecture portion is where you memorize stuff. Physio lab is like a combination of a physics lab (time vs force, graphs/charts), chem lab (some wet lab involved, same pre and post lab write up, observations, etc), and anatomy lab (fun part, you/partner/humans are guinea pigs). I didn't like the labs because it is very, very time intensive. You spend like 2 or 3 hours in lab, then you end up spending 2 or 3 days trying to figure out what your data means for each lab assignment (and there are many of them).
I found biochem to be one of the most challenging classes I've ever taken. There is not only an insane amount of memorization involved (names, enzymes, pathways, intermediate products), there is also application problems (number of atp/adp/fad/nad/fadh/nadh from the different pathways). There is no easy way to learn biochem, and it is easy to blame the professor. You want a knowledgeable professor or at least a good TA for this class (i'm not talking about one that regurgitates crap from the book) but one that is willing to break down all the major pathways into smaller pieces that you can actually grasp.
If you actually have to take all those classes at the same time, its definitely doable. I just hate to be you.
