You need to cover everything in ochem but you have to spend your time wisely as well. Look at it like this.. Ochem constitutes at most one half of the BS section of the MCAT(usually much less) and the ochem is quite general. Would it be advantageous to spend such a large amount of time going through that entire Berkeley ochem book when you can cover the same material in less detail and in far less time from a book like EK? I said this on a different thread and a few others agreed that we could have reviewed the EK ochem book for an hour prior to taking the mcat and been completely prepared for all the ochem on the exam. Not to say that this is a standard with the exam but it just doesn't make sense to go into the detail that Berkeley review offers in their ochem books while studying for the mcat. Their books rival undergrad ochem books at times and such an understanding of ochem rarely pays off on the mcat. Don't take what I'm saying as ochem is not important but rather not as valuble to understand in detail like subjects you would see in PS or BS. I've taken 3 mcats and the only ochem I have ever seen was sn1/sn2/e1/e2, stereochem, IR, basic lab techniques, basic reactions, and some basic biochem. I have personally never seen more than 2 passages and a handful of discretes with ochem as well. Others have had different experiences so take what I am saying with a grain of salt. Just keep in mind that there are different sources that can prepare you adequately and in far less time. Also remember that if you don't feel ready when the exam rolls around, postpone!