MCB 2000 Lecture Notes - Lecture 19: Glycerol, Sphingolipid, Hydrophile
Document Summary
Phospholipids: glycerol backbone, fatty acids at position 1 and 2 hydroxyl groups, polar group at position 3 hydroxyl group. Cis unsaturated fatty acids decrease packing of molecules in membrane. Carboxylic acid of fatty acid is esteri ed to hydroxyl group of glycerol - this ester bond is covalent. Cholesterol can increase/decrease uidity depending on location. -oh groups form h-bonds with carbonyl of phospholipid head. Can form complex with speci c phospholipids (sphingolipids) Fused ring structure is rigid -> can disrupt regular interactions between phospholipid tails -> increasing membrane uidity. Melting temp depends on fatty acid chain length and extent of unsaturation. Lipids can undergo rotational and lateral movement. Fluorescence recovery after photobleaching measures lateral movement of lipids and proteins. Proteins span the membrane (integral) or are loosely associated (peripheral) Can only be removed by denaturing the membrane. Dissociated with mild detergent or high salt concentration.
