BIO 1140 Lecture Notes - Lecture 4: Phosphatidylethanolamine, Glycosphingolipid, Sphingosine
27 Feb 2017
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Document Summary
Axon growth requires the supply of building blocks, cycling filaments in the growth cone, connections between growth cone filaments and the growth substrate and a way to translate external, directional cues into pathfinding decisions. Why do we have membranes: boundary; selective permeability, organize and scaffold, regulate solute transport, receive signals, communication. They all have 2 layers of phospholipids. Fluidity: within each layer the lipids continuously change places, rarely a change from one layer to the other occurs, membranes are asymmetric- both layers are different! Sphingomyelin: glycolipids (glycosphingolipids_ are 1 or 2 fatty acid chains with single or multiple sugar groups attached via glycerol or sphingosine. Important for cellular recognition, antigens: sterols are 4-ring hydrocarbons present only in eukaryotes. They play an important role in fluidity; both in terms of arrangement and in relation to temperature (buffers) Properties of the lipid bilayer: membrane asymmetry (both layers are different, membrane fluidity. Length and saturation of fatty acid chains.
