Phospholipids, the major class of membrane lipids have both a hydrophilic and a hydrophobic moeity. Phospholipids spontaneously form lipid bilayers in aqueous media. Along with phospholipids, proteins are a major component of biological membranes. The proteins and lipids of membrane assemblies are held together mainly by intermolecular forces. While lipids constitute a permeability barrier, proteins mediate membrane functions. The more saturated the fatty acid chains of the fatty acids, the less flexible and fluid the membrane. The fluid mosaic model conceptualizes a biological membrane as a two dimensional solution. The lipid bilayer is the solvent for integral membrane proteins. Unless specially restricted, lateral diffusion of membrane proteins is permitted whereas rotation from one side of the membrane to the other is not. Proteins are either extrinsic or intrinsic.












The WikiPremed MCAT Course is a comprehensive course in the undergraduate level general sciences. Undergraduate level physics, chemistry, organic chemistry and biology are presented by this course as a unified whole within a spiraling curriculum. Please read our policies on Privacy and Shipping & Returns.  Contact Us. MCAT is a registered trademark of the Association of American Medical Colleges, which does not endorse the WikiPremed Course. WikiPremed offers the customers of our publications or our teaching services no guarantees regarding eventual performance on the MCAT.


Creative Commons License
WikiPremed is a trademark of Wisebridge Learning Systems LLC. The work of WikiPremed is published under a Creative Commons Attribution NonCommercial ShareAlike License. There are elements of work here, such as a subset of the images in the archive from WikiPedia, that originated as GNU General Public License works, so take care to follow the unique stipulations of that license in printed reproductions.