Biology 2382B Lecture Notes - Glucocerebroside, Sphingomyelin, Alkanolamine
21 May 2013
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Document Summary
Fatty acid long hydrocarbon chain attached to a polar head group amphipathic. More than one double bond = polyunsaturated. Effect of double bond on structure of fatty acid. Temperature increases with chain length, decreases with unsaturation (37 degrees) Melting point increases with increasing chain length but decreases with increasing unsaturation. Phosphoglyceride = derived from 3 carbon glycerol and 3-phosphate scaffold to which the polar head group and 2 acyl chains are attached. Glycolipid = head group is sugar (abundant in nervous tissue) Sterols amphipathic intercalate between phospholipids where they orient themselves with their polar hydroxyl groups facing the same direction as the polar head groups of the fatty acids add cholesterol increase diameter and thickness change properties of membrane. Cis double bonds more cis = more fluid. Cell (membrane proteins) proteins can move laterally. Diffusion 10x slower in plasma membranes than pure bilayers: closed compartments. Vesicle membrane: cytosolic face = external face: semi-permeable. Small, uncharged or hydrophobic molecules pass freely.
