BIOCH200 Lecture Notes - Lecture 20: Formal Charge, Synthetic Membrane, Melting Point
30 Oct 2016
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Document Summary
Some glycerophospholipids: will spontaneously form structures with each other, form bilayers, which are major components of biological membranes. Due to geometry: contains 2 hydrophobic (non-polar) groups and 1 hydrophilic (polar) group, variations exist in both polar head groups and acyl chains, affecting size and m. p. Cholesterol is an important membrane lipid in mammals: ~35% of mammalian membranes. Maintains fluidity and rigidity: rigid, non-polar structure. Due to hydrocarbon/ring structures (27 c, 1 oh: weakly amphipathic (even though has a single -oh group, no formal charge, humans manufacture more cholesterol than we eat. Oh associates with polar headgroups of other lipids: cholesterol buries itself in the hydrophobic core, doesn"t form any specialized structures with water because it just doesn"t have the proper characteristics. Fatty acids tend to form a micelle structure when mixed with water. Micelles or bilayers in water: these arrangements eliminate. Unfavourable contact between water and hydrophobic tails, yet permits solvation of polar head groups.
