BIO 1140 Lecture Notes - Lecture 7: Electron Microscope, Photobleaching, Phospholipid
24 Aug 2016
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Document Summary
Membrane asymmetry: each side has to interact with a different environment. Can use the asymmetry as signaling by flipping the phospholipid bilayers to signal the cell is in trouble. If it is stiff it will not be able to accomplish transport by the proteins changing shape, passive diffusion will not be able to take place. Which type of polar head group, saturation, the presence of sterols, temperature. The temperature will influence fluidity because it influences how the phospholipids interact by changing the rate of movement of the molecules. To compensate for high temperature, slow down enzymes that introduce double bonds to increase saturation and decrease fluidity. Not all phospholipids are the same, introduce nonpolar heads with shorter chains. Enzymes (desaturase) are important for maintaining optimal fluidity by introducing or taking away double bonds to increase or decrease saturation. Pe phospholipid heads confers more fluidity than pc and changing the ratio between them will affect fluidity of the membrane.
