BIOL 1103 Chapter Notes - Chapter 7: Lysosome, Exocytosis, Vacuole

• School: Carleton University
• Department: Biology
• Course: BIOL 1103
• Professor: Iain Lambert

Document Summary

Plasma membrane separates cell from its surroundings and is 8nm thick. Membranes consist of lipids and proteins and some carbohydrates. The lipids are amphipathic (have both polar (head) and non-polar (tail) regions) and so are most membrane proteins. Fluid mosaic model: the membrane is a mosaic where protein molecules drift laterally in a fluid bilayer of phospholipids. How long a membrane stays fluid as temp decreases depends on number of unsaturated lipids present, the more lipids present the longer it stays fluid. Membranes must be fluid to work, the fluidity affects permeability and ability of membrane proteins to get where they need to be. Integral proteins: proteins that penetrate the hydrophobic interior of lipid bilayers. Peripheral proteins: proteins that are not embedded in the lipid bilayer but are usually attached to integral proteins. Some proteins are also attached to the cytoskeleton or the ecm.