Biology 1202B Lecture Notes - Lecture 2: Unsaturated Hydrocarbon, Fluid Mosaic Model, Alkane
14 Jul 2016
School
Department
Course
Professor
Document Summary
Membranes are composed of a selectively permeable phospholipid bilayer. Proteins embedded or attached to the membrane perform membrane functions. Membrane fluidity is influenced by the type of fatty acid and temperature. As temperature drops, the random motion of lipids slows down. When gelling begins to occur, that means that the membrane is not functioning properly. More saturated molecules will have a lower gelling point of the membrane. Keeping membranes fluid is essential to cell function. Organisms can regulate the degree of fatty acid unsaturation of the fatty acids. Desaturases can introduce double bonds to fatty acids. Alters organisms to respond to temperature changes in the environment. Saturated fatty acids linear (allows lipid molecules to pack tightly together) Unsaturated fatty acids less linear (allows fluidity in membrane) Similar to lipids, sterols also influence membrane fluidity. Like fatty acids hydrophilic interacts with aqueous hydrophobic interacts with the membrane interior. Membrane proteins are dispersed and individually attached or inserted into the phospholipid bilayer.
