1. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 15 Lipids 15.5 Glycerophospholipids 1 Glycerol PO 4 Amino alcohol Fatty acid

2. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Glycerophospholipids Glycerophospholipids are the most abundant lipids in cell membranes composed of glycerol, two fatty acids, phosphate, and an amino alcohol 2 Glycerol PO 4 Amino alcohol Fatty acid

3. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Polarity of Glycerophospholipids Amino alcohols found in glycerophospolipids have two nonpolar fatty acid chains, a phosphate group, and a polar amino alcohol are ionized at physiological pH of 7.4 CH 3 + + HO−CH 2 −CH 2 −N−CH 3 HO−CH 2 −CH 2 −NH 3 Choline CH 3 + Ethanolamine NH 3 HO−CH 2 −CH−COO − Serine 3

4. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Lecithin and Cephalin Lecithin and cephalin are types of glycerophospholipids that are abundant in brain and nerve tissues found in egg yolk, wheat germ, and yeast 4

5. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Structure and Polarity of a Glycerophospholipid 5 Glycerophospholipids have both polar and nonpolar regions that allow them to interact with polar and nonpolar substances have a polar head containing the ionized amino alcohol and phosphate portion, which is strongly attracted to water have a hydrocarbon tail portion only soluble in nonpolar substances such as lipids are the most abundant lipids in cell membranes and play an important role in cellular permeability

6. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Structure and Polarity of a Glycerophospholipid 6 (a) In a glycerophospholipid, a polar head contains the ionized amino alcohol and phosphate groups, while the two fatty acids make up the nonpolar tails. (b) A simplified drawing indicates the polar region and the nonpolar region.

7. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Identify each of the following as a fatty acid, triacylglycerol, amino alcohol, or glycerophospholipid. A. glyceryl trioleate B. cephalin C. choline D. palmitic acid 7

8. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Identify each of the following as a fatty acid, triacylglycerol, amino alcohol, or glycerophospholipid. A. glyceryl trioleate triacylglycerol B. cephalin glycerophospholipid C. cholineamino alcohol D. palmitic acidfatty acid 8

9. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Draw the condensed structural formula of a cephalin that contains stearic acid and serine. 9

10. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Draw the condensed structural formula of a cephalin that contains stearic acid and serine. 10