I would recommend checking out later sections of this book http://www.amazon.com/Mathematical-Biology-Introduction-Interdisciplinary-Mathematics/dp/0387952233 (I can PM you a pdf if you want it). It goes into protein-protein bonding and protein-small molecule reactions in glorious mathematical sparseness, succinctly covers molecular biology/bioinformatic screens, and of course covers everyone's favorite intro PDE- the predator prey model; even after taking upper level undergraduate biochem/molecular biology courses seeing it all put so succinctly was a real treasure. Some of the math is relatively advanced for a developmental math course, but given that all of your biology/chemistry majors should have covered this material before (sans math in most cases) it shouldn't be too hard for them to jump into.