BIOL130 Lecture Notes - Lecture 3: Phospholipid Scramblase, Red Blood Cell, Secretion
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10 Dec 2016
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All membrane lipids are amphipathic (glycolipid, phospholipid, cholesterol) Top is always polar (like 4 carbon rings in cholesterol) What you want in healthy membrane: fluidity- critical for cell survival and function. If you de(cid:272)(cid:396)ease te(cid:373)pe(cid:396)atu(cid:396)e, they"ll (cid:373)o(cid:448)e less a(cid:374)d less u(cid:374)til the fatty a(cid:272)ids gel a(cid:374)d solidify (not compatible in nature) Increasing cholesterol, it will be less fluid (body temperature) Can be used for secretory pathway (destined for secretion from inside to outside of cell) Scramblase takes random phospholipids from cytosolic side and shifts over to other side. Enzyme in er that evens out two layers (important because dragging leaflets to other side) Fresh new phospholipid from er is incorporate in golgi membrane and another enzyme expressed in the golgi called flipases selectively flip two across to the other side (ps and pe) Now we have more ps and pe on the other side (cytosolic side)