BIOL 1010 Lecture Notes - Lecture 5: Unsaturated Hydrocarbon, Lipid Bilayer, Alkane

• School: Dalhousie University
• Department: Biology
• Course: BIOL 1010
• Professor: M.Mc Carville

Document Summary

Ch. 7- cellular membranes are fluid mosaics of lipids and proteins. Lipids and proteins are the staple ingredience of membranes. Most abundant in most membranes is phospholipids. A phospholipid is an amphipathic molecule meaning it has hydrophilic region and hydrophobic region. Phospholipid can exist as a stable boundary between 2 aqueous compartments because the molecular arrangement shelters the hydrophobic tails of phospholipids from water while exposing hydrophilic heads to water. In the fluid mosaic model, the membrane is a mosaic of protein molecules bobbing in a fluid bilayer of phospholipids. Membrane is held together primarily by hydrophobic interactions, much weaker than covalent bonds. The temperature at which a membrane solidifies depends on the types of lipids it is made of. Membrane remains fluid to a lower temperature if it is rich in phospholipids with unsaturated hydrocarbon tails. Unsaturated tails cannot pack together as closely as saturated hydrocarbon tails, makes membrane more fluid.