Biochemistry 2280A Study Guide - Caveolae, Oncogene, Bacteriorhodopsin

• School: Western University
• Department: Biochemistry
• Course: Biochemistry 2280A
• Professor: Christopher Brandl

Document Summary

Proteins make up about 50% of the mass of typical biological membranes (fig 11-4, p. 365). Behaviour of proteins within the lipid bilayer is described by the fluid mosaic model, which states that proteins are free to diffuse laterally within the bilayer, unless their movement is restricted by cellular components (fig. 11-20, p. 372): transporters: ions and most polar molecules do not readily cross the hydrophobic membrane (fig 12-2, p. 389). Transport proteins are required to move ions and polar molecules between compartments of the cell, or between the inside and outside. Most transporter proteins are specific for a particular substrate or a small set of substrates. Anchor proteins bind to other macromolecules on one or both sides of the membrane. Like transport proteins, most receptors recognize a very specific molecular signal. For example, the insulin receptor binds and is activated by insulin but not other molecules: enzymes: proteins that catalyze chemical reactions can be associated with membranes.