From what I remember, the bio section was primarily definitions and typical examples of various concepts. For many of the questions, if I had any idea of the concept, the answer was obvious. I'd recommend trying to cover as much volume as possible, because hitting specifics is nearly impossible. I studied the entire Kaplan book and 6 or 7 practice tests and still saw material that was completely new to me. Unless you are trying to get a perfect score, study in a way that will maximize your correct answers rather than worry about specifics that may or may not be on the test. Its unlikely youll get more than 1 or 2 biochem questions and it they may not even cover those cycles. Understand the basic concepts, and chances are you'll be able to derive the answer from the choices by elimination even if you don't know the material exactly.