BIO 1140 Lecture Notes - Lecture 5: Phosphatidylinositol, Cholesterol, Membrane Fluidity

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High temp = more vibrations = more fluidity. Low temp = less vibrations = less fluidity. Unsaturated fats onto the chain introduce more fluidity only for that area though. Cholesterol fills in the spaces in between the membrane causing less fluidity, more stability. Maintain fluidity in low temperatures, works against the extremes of temperature. Sterols in compacted lipids causing them to spread out making it more fluid. Not all lipids have same polar heads because they are different, phosphtialprolene and phosophtiethylene influcenes fluidity. The ability to change the membrane lipid composition in response to the environment in order to maintain membrane fluidity. Adjust composition to adapt to the temperatures to keep fluidity in the membrane. Going to hot to cold, membrane will become more fluidity, cholesterol will increase, and the pc/pe ratio will decrease. Want more polar phospholipids more pe for more fluidity. 3 types of membrane proteins: integral proteins ion channels, transporters, receptors.