BIOL 102 Chapter Notes - Chapter 6: Peripheral Membrane Protein, Lipid Bilayer, Lipid-Anchored Protein
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16 Dec 2013
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Three primary components of the plasma membrane: phospholipids, proteins and carbohydrates. Can be covalently linked to a fatty acid post-translationally to anchor covalently to a protein to become stably inserted. same move laterally/rotationally, slowly. Scramblase proteins - method for moving phospholipids between leaflets (along the concentration gradient) Flippases - move lipid from the outer to thinner leaflet with the energy from atp hydrolysis. Floppases - opposite of flippases, still with the assistance of atp hydrolysis. This attachment is done post-translationally after a polypeptide is created. The fatty acid tail of the lipid anchor keeps the protein firmly bound in the membrane leaflet in which it is embedded. Both transmembrane proteins and lipid anchored proteins are classified as. Integral membrane proteins - they cannot be released from the membrane unless the integrity of the membrane is disrupted. Because of their hydrophobic interiors, phospholipid bilayers present a good barrier to the movement of ions and hydrophilic molecules.