COM 1000 Study Guide - Osmosis, Amphiphile, Organelle
Document Summary
They have hydrophilic/polar heads and hydrophobic/nonpolar tails. Form a stable bilayer w/ head out and tail in. Hydrophobic inside prevents large or charged molecules from getting (amphipathic) through. Phospholipids move laterally more often than vertically: membrane is a fluid mosaic lipids & proteins embedded in bilayer, cholesterol (a lipid) helps stabilize animal cell membranes at different temperatures, two major proteins in membrane. Integral/transmembrane go all the way through the membrane; usually channels for transport. Peripheral on surface/edge; stick up on outside of membrane: membrane shows sidedness . Exterior carbs, extracellular matrix: glycoproteins proteins with carbs attached; critical in cell recognition, basically id your cells so your body knows they"re yours, function, organizes chemical activities of cell. Controls what goes in/out of cell (semi-permeable) Provides reaction surfaces and organizes enzymes and their substrates: membrane proteins do a lot of things. Enzymatic activity protein may also double as an enzyme.