Go to all of your biochemistry classes and laboratory sessions. If you show up to class and lab, your professor will see that you are interested in the class and are trying to do well. This will make you more likely to pass. Plus, being at class will simply help you learn the material better.
Take notes in class. Try to be as comprehensive as possible. If your professor spends a lot of time on something or says that something in particular is important, write it down in your biochemistry notebook. Writing things down can help you remember them later (like at test time).
Pay attention to the professor during class. If you are not going to pay attention, there is probably no point in you being in class anyway. Anything that you listen to in class may stick with you come exam or quiz time.
Do your homework. If you are assigned homework or are told to write up laboratory reports, do it. Doing homework is not technically studying, and if you do your homework and do it well, this portion of your grade will go a long way towards helping you pass the class as a whole.
Read your biochemistry textbook. You don't have to study it or even read it multiple times. Just read the parts that you are assigned once. If you read, you may remember what you have read come exam time.
Ask questions. You can either ask your professor questions during your biochemistry class or your biochemistry lab session, or you can go to your professor's office hours outside of class. Make sure that any questions that you do have are addressed.