External Resourses

The Medical Biochemistry Page - Receptors for Peptide Hormones

Kimball's Biology Pages - Proteins, peptides, and modified amino acids

The Medical Biochemistry Page - Signal Transduction
Excellent, comprehensive (somewhat advanced) discussion of a very important topic for the MCAT. Don't let the advanced material intimidate you away from the main concepts. You don't have to memorize everything. Working to be able comfortably comprehend discussions at this level, not knowing everything beforehand, is a primary task for MCAT preparation.