Biology And Biomedical Sciences BIOL 2960 Lecture Notes - Lecture 8: Sodium-Potassium Alloy, Conformational Change, Hydrolysis
15 Feb 2017
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Document Summary
Nonpolar structures are the most permeable (due to the hydrophobic tails of phospholipids) Polar structures are mostly impermeable for the same reason. Larger sized molecules also have trouble crossing the membrane. Organization and function of membrane depends on the constituent lipids, proteins, and carbohydrates. Unsaturated fatty acids in phospholipids cause bends in the tails, resulting in less tightly packed phospholipids which increases membrane fluidity. Continuous phospholipid bilayer with proteins embedded and inserted. Indirectly associated with membrane via interaction with integral protein, head groups, or lipid modifications. Integral membrane proteins often have membrane spanning alpha helices. R groups of helices interacting within the membrane are nonpolar. R groups in an aqueous environment are polar. Some membrane proteins are made up of beta sheets. Antiparallel beta sheets roll up to create a hollow cylinder or pore. R groups on inside of pore polar. Rest of the protein lies outside the membrane. Hydrophobic amino acids are in the lipid bilayer.
