Physiology 3140A Lecture Notes - Lecture 9: Sphingosine, Glycolipid, Thalassemia
7 Oct 2016
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Document Summary
Lipid bilayer dynamic structure composed of phospholipids continuous replacement of phospholipids through recycling. Membranes contain lipid, protein and also glycolipids and glycoproteins compositions of lipid bilayers differ between different membranes recycling between existing membranes: grows by inserting individual components like proteins and lipids. Asymmetry of lipid bilayer inner and outer leaflets have different lipid types provides curvatures of membranes: directs overall shape of cell or organelle. Membrane lipids glycerolipids have glycerol-derivative core: aka glycerophospholipids sphingolipids contain sphingosine derivative, glycolipid/glycosphingolipids have glucoses attached to sphingolipid sterols (e. g. cholesterol, cholesterol found on either leaflet of a membrane. 4 types, each composed of a phosphatidyl + r group: phosphatidyl-inositol (pi, phosphatidyl-serine (ps, phosphatidyl-choline (pc, phosphatidyl-ethanolamine (pe) Pi and ps have a neutral r group and so their net charge is negative. Pc and pe have a positively charged r group so their net charge is neutral. Phosphatidylcholine is most common; 35-75% of membrane lipids. Substantial portion of membrane is negatively charged (~20%)
