Biology  5/e   Raven/Johnson
	Student   Online Learning Center

Polar nature of water: Oxygen atoms attract electrons more strongly than do hydrogen atoms. This relationship causes the oxygen end of the molecule to be electron rich and the hydrogen end of the molecule to be electron poor. Thus, the water molecule has one pole that is more negative and another that is more positive.

Hydrogen bonds: The weak attraction of positive ends of polar molecules to the negative ends of other molecules is referred to as a hydrogen bond.

Structure of fat molecules: Fat molecules are composed of one molecule of a three carbon alcohol called glycerol to which are attached three fatty acids.

Hydrophobic: Because water molecules are polar and form bonds with other polar molecules, nonpolar molecules are pushed aside. This segregation gives the impression of nonpolar molecules withdrawing from water molecules as if fearing the water. Such nonpolar molecules are called hydrophobic.

Types of membrane proteins: Three types of proteins are found in membranes: channel-forming proteins, receptors, and markers.

Copyright ©1998 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use and Privacy Policy.
McGraw-Hill Higher Education is one of the many fine businesses of The McGraw-Hill Companies.
For further information about this site contact mhhe_webmaster@mcgraw-hill.com.