Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Lipids - CHEM225
Transcript
Chapter 15 Lipids 1 15.5 Glycerophospholipids Fatty acid Glycerol Fatty acid PO4 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Amino alcohol Copyright © 2012 by Pearson Education, Inc. Glycerophospholipids 2 Glycerophospholipids are • the most abundant lipids in cell membranes • composed of glycerol, two fatty acids, phosphate, and an amino alcohol Fatty acid Glycerol Fatty acid PO4 Amino alcohol Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Polarity of Glycerophospholipids 3 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 CH3 + + HO−CH2−CH2−N−CH3 Choline CH3 HO−CH2−CH2−NH3 + Ethanolamine NH3 HO−CH2−CH−COO− Serine Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Lecithin and Cephalin 4 Lecithin and cephalin are types of glycerophospholipids that are • abundant in brain and nerve tissues • found in egg yolk, wheat germ, and yeast 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 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. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check 7 Identify each of the following as a fatty acid, triacylglycerol, amino alcohol, or glycerophospholipid. A. glyceryl trioleate B. cephalin C. choline D. palmitic acid Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 8 Identify each of the following as a fatty acid, triacylglycerol, amino alcohol, or glycerophospholipid. A. glyceryl trioleate B. cephalin triacylglycerol glycerophospholipid C. choline D. palmitic acid amino alcohol fatty acid Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check 9 Draw the condensed structural formula of a cephalin that contains stearic acid and serine. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 10 Draw the condensed structural formula of a cephalin that contains stearic acid and serine. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc.
