BIOL 1090 Lecture Notes - Lecture 15: Integral, Organelle, Facilitated Diffusion

• School: University of Guelph
• Department: Biology
• Course: BIOL 1090
• Professor: Andrew Bendall

Document Summary

All membranes share common properies: about 6nm thick (with associated water, stable, flexible, capable of self assembly (ex. liposomes) Membranes have diferent funcions, in diferent cells and within an individual cell. Diferent membranes contain diferent types of lipids and proteins. Lipid rafts membrane micro- domains: lipid rats are small areas of the plasma membrane that are enriched in certain types of lipids (ex. Cholesterol: rats are relaively rigid, some membrane proteins accumulate in rats, may form funcional component (nature/funcion of rats is controversial, figure schemaic diagram of lipid rat within a membrane. Down a concentraion gradient (low is downhill) Ion channels are formed by integral membrane proteins that line an aqueous pore: channels are selecive, allowing only one type of ion to pass, ions move down concentraion gradient, oten channels are gated (can be opened or closed) Channel responds to changes in charge across membrane. Channel responds to binding of speciic molecules (a ligand .