Biology 2382B Lecture Notes - Lecture 13: Glycosylphosphatidylinositol, Lipid Bilayer, Integral Membrane Protein
16 Aug 2017
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Document Summary
Membranes have a lot of proteins in it, different from in vitro: phospholipids are amphipathic, a cell membrane is not only phospholipids, there are many molecules in a biomembrane. Bio membrane has certain properties: fluidity: want semi-fluid in human. Melting point increases with increasing chain length, but melting point decreases with increasing unsaturation. Especially if we link those proteins to the cytoskeleton then it would not be very fluid limit fluidity: also temperature increase = increase fluidity. But our bodies do not use this to regulate fluidity since we have a constant body temperature: closed compartments, semi-permeable, asymmetric. Diffusion 10x slower in plasma membranes than pure bilayers (since proteins) Graph: after bleaching the fluorescence turns to 0. Now we"re looking for recovery over time: the amount of recovery that we want is relative. In this graph we get 50% since 50% of proteins are mobile and the other 50% are immobile.
