1. Chapter Nineteen Lipids

2. Copyright © Houghton Mifflin Company. All rights reserved.19 | 2 →CO 19.1 Fats and oils are the most widely occurring types of lipids. Thick layers of fat help insulate polar bears against the effects of low temperatures. Lipids cont’d Dan Guravich / Photo Researchers

3. Copyright © Houghton Mifflin Company. All rights reserved.19 | 3 ←Fig. 19.1 The structural formulas of these types of lipids illustrate the great structural diversity among lipids. Lipids cont’d

4. Copyright © Houghton Mifflin Company. All rights reserved.19 | 4 →Fig. 19.2 The melting point of a fatty acid depends on the length of the carbon chain and on the number of double bonds present in the carbon chain. Lipids cont’d

5. Copyright © Houghton Mifflin Company. All rights reserved.19 | 5 ←Fig. 19.3 Four 18-carbon fatty acids, which differ in the number of double bonds present. Lipids cont’d

6. Copyright © Houghton Mifflin Company. All rights reserved.19 | 6 →Fig. 19.4 Adipoctyes are the body’s triacylglycerol- storing cells. Lipids cont’d © Manfred Kage / Peter Arnold, Inc.

7. Copyright © Houghton Mifflin Company. All rights reserved.19 | 7 Fig. 19.5 Structure of the simple triacyglycerol produced from the triple esterification reaction between glycerol and three molecules of stearic acid. Lipids cont’d

8. Copyright © Houghton Mifflin Company. All rights reserved.19 | 8 →Fig. 19.6 Mixed triacylglycerol in which three different fatty acid residues are present. Lipids cont’d

9. Copyright © Houghton Mifflin Company. All rights reserved.19 | 9 Fig. 19.7 Triacylglycerols from (a) fat and (b) oil. Lipids cont’d

10. Copyright © Houghton Mifflin Company. All rights reserved.19 | 10 →Fig. 19.8 Percentages of saturated, monosaturated, and polyunsaturated fatty acids. Lipids cont’d

11. Copyright © Houghton Mifflin Company. All rights reserved.19 | 11 ←Fig. 19.9 Fish that live in deep, cold water are better sources of omega-3 fatty acids than other fish. Lipids cont’d © IFA / Peter Arnold, Inc.

12. Copyright © Houghton Mifflin Company. All rights reserved.19 | 12 ←Table 19.2 Lipids cont’d

13. Copyright © Houghton Mifflin Company. All rights reserved.19 | 13 CC 19.1 Tree nuts and peanuts Lipids cont’d

14. Copyright © Houghton Mifflin Company. All rights reserved.19 | 14 ←Table 19.3 Lipids cont’d

15. Copyright © Houghton Mifflin Company. All rights reserved.19 | 15 →Fig. 19.10 Complete and partial hydrolysis of a triacylglycerol. Lipids cont’d

16. Copyright © Houghton Mifflin Company. All rights reserved.19 | 16 ←CC 19.2 Lipids cont’d

17. Copyright © Houghton Mifflin Company. All rights reserved.19 | 17 ←CC 19.3 Lipids cont’d

18. Copyright © Houghton Mifflin Company. All rights reserved.19 | 18 Fig. 19.11 Structural equation for the complete hydrogenation of a triacylglycerol with oleic acid and fatty acid residue. Lipids cont’d

19. Copyright © Houghton Mifflin Company. All rights reserved.19 | 19 ←CC 19.4 Lipids cont’d

20. Copyright © Houghton Mifflin Company. All rights reserved.19 | 20 →Fig. 19.12 The oils present in skin perspiration rapidly undergo oxidation. Lipids cont’d BRI / Vision / Photo Researchers

21. Copyright © Houghton Mifflin Company. All rights reserved.19 | 21 Lipids cont’d CAG 19.1

22. Copyright © Houghton Mifflin Company. All rights reserved.19 | 22 Fig. 19.13 (a) structural formula and (b) molecular model showing the “head and two tails” structure of a phosphatidyl-choline molecule. Lipids cont’d

23. Copyright © Houghton Mifflin Company. All rights reserved.19 | 23 Fig. 19.14 Molecular models for (a) sphingosine and (b) sphingophosopholipid. Lipids cont’d

24. Copyright © Houghton Mifflin Company. All rights reserved.19 | 24 Lipids cont’d ←CC 19.4

25. Copyright © Houghton Mifflin Company. All rights reserved.19 | 25 ←Fig. 19.15 Structural formula and model for the cholesterol molecule. Lipids cont’d

26. Copyright © Houghton Mifflin Company. All rights reserved.19 | 26 →Fig. 19.16 A severely occluded artery. Lipids cont’d Howard Socurek / Medichrome

27. Copyright © Houghton Mifflin Company. All rights reserved.19 | 27 ←Table 19.4 Lipids cont’d

28. Copyright © Houghton Mifflin Company. All rights reserved.19 | 28 ←Fig. 19.17 Cross section of a lipid bilayer. Lipids cont’d

29. Copyright © Houghton Mifflin Company. All rights reserved.19 | 29 →Fig. 19.18 Space-filling model of a section of a lipid bilayer. Lipids cont’d

30. Copyright © Houghton Mifflin Company. All rights reserved.19 | 30 ←Fig. 19.19 The kinks associated with cis double bonds in fatty acid chains prevent tight packing of the lipid molecules in a lipid bilayer. Lipids cont’d

31. Copyright © Houghton Mifflin Company. All rights reserved.19 | 31 →Fig. 19.20 Cholesterol molecules fit between fatty acid chains in a lipid bilayer. Lipids cont’d

32. Copyright © Houghton Mifflin Company. All rights reserved.19 | 32 ←Fig. 19.21 Proteins are important structural components of cell membranes. Lipids cont’d

33. Copyright © Houghton Mifflin Company. All rights reserved.19 | 33 Fig. 19.22 Three processes by which substances can cross plasma membrane. Lipids cont’d

34. Copyright © Houghton Mifflin Company. All rights reserved.19 | 34 ←Fig. 19.23 Line-angle structural formulas for cholesterol, cholic acid, and two deoxycholic acids. Lipids cont’d

35. Copyright © Houghton Mifflin Company. All rights reserved.19 | 35 →Fig. 19.24 Structures of glycocholic and taurocholic acid. Lipids cont’d

36. Copyright © Houghton Mifflin Company. All rights reserved.19 | 36 ←Fig. 19.25 A large percentage of gallstones are almost pure crystallized cholesterol. Lipids cont’d C. James Webb / Phototake

37. Copyright © Houghton Mifflin Company. All rights reserved.19 | 37 →Fig. 19.26 Selected sex hormones and synthetic compounds that have similar actions. Lipids cont’d

38. Copyright © Houghton Mifflin Company. All rights reserved.19 | 38 ←CC 19.5 Lipids cont’d

39. Copyright © Houghton Mifflin Company. All rights reserved.19 | 39 ←Fig. 19.27 Selected adrenocorticoid hormones and related synthetic compounds. Lipids cont’d

40. Copyright © Houghton Mifflin Company. All rights reserved.19 | 40 →Fig. 19.28 Relationship of the structures of various eicosanoids to their precursor, arachidonic acid. Lipids cont’d

41. Copyright © Houghton Mifflin Company. All rights reserved.19 | 41 Lipids cont’d  CC 19.6

42. Copyright © Houghton Mifflin Company. All rights reserved.19 | 42 Fig. 19.29 A biological wax has a structure with a small, weakly polar “head” and two long, nonpolar “tails”. Lipids cont’d

43. Copyright © Houghton Mifflin Company. All rights reserved.19 | 43 →Fig. 19.30 Plant leaves often have a biological wax coating to prevent excessive loss of water. Lipids cont’d © Kevin Schaefer / Peter Arnold, Inc.

44. Copyright © Houghton Mifflin Company. All rights reserved.19 | 44 Lipids cont’d  CAG 19.3