BIOL 1000 Chapter Notes - Chapter 5: Exocytosis, Electric Potential, Pinocytosis
2 Apr 2017
School
Department
Course
Professor
Document Summary
Biol 1000 chapter 5: cell membranes & signalling. Plasma membrane is a selectively permeable barrier that allows for the uptake of key nutrients and elimination of waste products while maintaining a protected environment for cellular processes to occur. Membrane structure is based on the fluid mosaic model which proposes that membranes are not rigid with molecules locked into place but rather consist of proteins that move around within a mixture of lipid molecules. Most membranes contain an assortment of types of proteins. Proportion of lipid and protein within a membrane depend on the type of membrane. Fluid mosaic model proposes : membranes are fluid. Lipid molecules of bilayer vibrate, flex back and forth, move sideways and exchange places within the same bilayer half. Proteins (b/c they are larger than lipids) move more slowly in the fluid environment of the membrane: membrane asymmetry. Reflects differences in the functions performed by each side of the membrane.
