BIOL 200 Lecture Notes - Lecture 5: Lipid Bilayer, Flippase, Micrograph
Document Summary
Ans: they self assemble into bilayer in water -> laws of thermodynamics. Ans: c does not have much polarity; hydrophobic. Hydrophilic head, hydrophilic tail possible for bilayer formation (amphipathic). Needs the right geometry to spontaneously form into bilayer. B is correct, because it has hydrophilic head and hydrophobic tail and the geometry is favoured. Experimental evidence for bilayer formation by phospholipids: tem micrograph, form planar bilayers across a small hole between 2 compartments. Heteropolymers = different kinds of monomers (triacylglycerol + 3 fatty acid) ** not all lipids form bilayers (ex. micelle, non polar lipids) Enzymes like flippase flips lipid from one side to another. The most abundant lipids in cell membranes are phospholipids. These lipids are in biological membranes as well! Making sure the water molecules are free to move. Must be able to associate with water. Must form relatively stable sheets in water instead of dispersing entirely.
