BIOL 2021 Lecture Notes - Glycosylphosphatidylinositol, Lipid Bilayer, Membrane Protein
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Document Summary
Biol 2021 march 12 2009- lecture- chapter 10. Membrane proteins perform most of the membranes specific tasks and therefore give each type of cell membrane its characteristic functional properties. Amounts of protein vary according to membrane function as well. Typical plasma membrane has amount half its mass as protein. Mainly defined by cannot be washed off with high salt soltutions ; membrane must be disrupted with detergent in order to be accessed and purified. Protein that is retained in a membrane by virtue of one or more domains that span or are embedded in the lipid bilayer. Transmembrane proteins and many proteins held in the bilayer by lipid groups or hydrophobic polypeptide regions that insert into the hydrophobic core of the lipid bilayer. Single pass transmembrane protein: polypeptide chain crosses only once. Multipass transmembrane proteins: polypeptide chain crosses multiple times. Peptide chain can form b barrel (b sheet rolled into barrel) ie. in porin proteins.