BIOL 1001 Chapter : Chapter Five
Document Summary
Chapter five: cell membrane structure 9/25/2012 3:59:00 pm. The phospholipid content of red blood cells is just enough to cover the cell with two layers. The red blood cell has no internal membranes. Biological membranes contain proteins: membranes isolated from red blood cells contain proteins in addition to lipids. Some of the recognition keys on the surface of cells are glycoproteins: glycoproteins: proteins which have a carbohydrate attached to them. Transport across membranes: transport is movement, require two factors, movement must be through a fluid. Liquid or gas: there must be a concentration gradient. Difference in the amount of molecules from one place to another: passive transport: movement down a concentration gradient, much of the movement of substances across membranes occurs by diffusion and therefore is a form of passive transport. Energy-requiring transport across membranes: cells need to move molecules against a concentration gradient, doing this requires energy because its fighting diffusing.
