i think in general most schools do not require biochem, and arizona is one of those schools. (correct me if i'm wrong gavin)
while there are the few schools (those that have been listed above) that do, MANY of the other schools still recommend taking more upper level science courses to have an idea on how well you will perform. biochem is one of the courses that i always see as a recommended class.
now how useful will biochem be and how accurate is this course as a predictor? i have yet to see as i am still a pre-dent hopeful. =)