BI110 Lecture Notes - Lecture 15: Lipid Bilayer, Alkane, Hydrophile
Document Summary
Saturated hydrocarbon tails make a membrane more viscous. Unsaturated hydrocarbon tails with kinks makes a membrane more fluid. A membrane that is too fluid becomes leaky which essentially is the only purpose of a membrane. If temperature drops low enough, phospholipid molecules become closely packed and forms a highly viscous semi solid gel (less fluid) At low temps enzymes and proteins cannot function if fluidity is not maintained. At high temps the membrane gets too fluid and becomes leaky (not good!) When cholesterol molecules are in a phospholipid bilayer, they act as a fatty acid tail in terms of the hydrophilic end/head(oh) and the hydrophobic tail. Cannot control temperature but can regulate itself to. A cell can continuously make phospholipids to regulate the amount of saturated and unsaturated fatty acids. Desaturases: enzymes that produce unsaturated fatty acids fatty acid synthesis.
