Enzyme Activity (Biology)
Lineweaver-Burke and inhibitors 
This is a nice complete explenation about inhibitors and its effects on Km and Vmax. The writing is easy to understand and logical. It also has a little java applet that shows the changes in the Lineweaver-Burke when changing Km and Vmax.
enzyme inhibitors 
A simple explanation of competitive and non-competitive enzyme inhibitors. I was going to post this link under biochemistry but it is definitely written by a biologist. It is definitely written in an easy to understand way. This review covers competative, and non-competative inhibitors. Michaelis-...
G-protein coupled receptor video 
This video explains the process of cellular signaling through G-protein-coupled receptors. This is a nice overview of GPCR's.
