PLSC 363 Chapter Notes - Chapter 5: Amphiphile, Lipid Bilayer, Osmosis
Document Summary
Selective permeability - plasma membrane allows some substances to cross it more easily than others. 5. 1 cellular membranes are fluid mosaics of lipids and proteins. Amphipathic - has both hydrophilic region and hydrophobic region. Phospholipid fluid mosaic model - membrane is a mosaic of protein molecules bobbing in a fluid bilayer of phospholipid. Weak rapid, lateral movements fluid until temp decreases enough to remain solid. Ex: fish living in extremely cold environment has high unsaturated hydrocarbon tails to remain fluid cholesterol helps membranes resist changes in fluidity when temp changes. Membrane - proteins embedded in fluid matrix of lipid bilayer integral proteins - penetrate hydrophobic interior of lipid bilayer transmembrane proteins (span membrane) Peripheral proteins - not embedded in lipid bilayer; loosely bound to surface of membrane. Signal transduction pathways convert a signal on a cell"s surface to a specific cellular response. Signal transduction pathways amplify the effect of a signal molecule.
