Biochemistry 3381A Study Guide - Quiz Guide: Fluid Mosaic Model, Lipid Bilayer, Amphiphile
27 May 2020
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Cylindrical shape means it favours a bilayer structure rather than a micelle: usually forms sheets but this means fatty acids are exposed to water on the side so self-seals to form sphere and cut this off. Can insert proteins into the membranes: used to deliver things to cells e. g. drugs. Exosomes little liposomes made by the cell for communication. Lateral diffusion occurs movement of lipids through the membrane. Rotation, flexion and flip flop can occur: flip flop is very rare because of hydrophilic/phobic barriers, they can be stimulated to do this by protein mediation. Steroid ring, polar hydroxyl head group, non-polar hydrocarbon tail: glycerophospholipid membrane. Inserts itself into membrane: there is a kink in the phospholipids so not usually densely packed, addition of cholesterol allows tighter packing and a stiffer, gel-like membrane. Sphingolipid membrane: longer, straighter fatty acid chains that are already packed tightly, with cholesterol it packs less tightly and increases fluidity.
