Basically all of the content for the MCAT will be found in the textbooks for the prerequisite classes. Whether or not it gets taught and whether or not you learn it is different. I had to learn about two chapters of biology and a chapter of chemistry on my own because in class we skipped over those sections. In general chemistry we were allowed to bring an index card of notes to exams and I got really good at writing small. It helped me get good grades, but I never really learned a lot of the material because I could just write it down. Of course, there was plenty of stuff that I'd learned in class but then forgotten and had to re-learn. Memorizing formulas was another headache. You will need to have all of your physics formulas and constants memorized, even the useless ones like gravitational attraction. I only memorized most of them, and I know it cost me a full point in the PS section. Like docelh said, the MCAT is a unique test and you will need to spend lots of time taking practice tests, and then reviewing the material on all the questions you missed. Don't forget the reading section, which won't be covered in any science class. That one's entirely up to you to study for.