1. Biochemistry- Ch 11. Carbohydrates 阮雪芬 NTUT Nov 4, 2002

2. Monosaccharides  The simplest carbohydrates  (C-H 2 O) n  Carbon hydrate

3. enantiomers Trioses

4. D-Aldoses Containing Three, Four, Five, and Six Carbon Atoms

9. D-Ketoses Containing Three, Four, Five, and Six Carbon Atoms

14. Pyranose Formation

17. Furanose Formation

19. Ring Structures of Fructose   : hydroxyl group attached to C-1 is below the plane of the ring.   : hydroxyl group attached to C-1 is above the plane of the ring.

20. Conformation of Pyranose and Furanose Rings  Pyranose and Furanose Rings are not planar.

21. Chair and Boat Forms of  - D - glucopyranose  The chair form is more stable.

23. 1 2 3 Envelop Conformations of  - D -ribose  Four atoms are nearly coplanar and the fifth is about 0.5Å away from this plane. 4 5 1 2 3 4 5

24. O-glycosidic bond and N-glycosidic bond NR 2 : N-glycosidic bond

25. Modified Monosaccharides

29. Maltose, a disaccharide

30. Common Disaccharides (1) glucose fructose Sucrase

31. Common Disaccharides (2) Lactase: in human beings  -galactosidase: in bacteria galactose glucose

32. Common Disaccharides (3) glucose Maltase

33. Electron Micrograph of a Microvillus

34. Polysaccharides  Large polymeric oligosaccharides  Play vital roles in energy storage and in maintaining the structural integrity of an organism.  If allof the monosaccharides are the same,these polymers are called homopolymers.  In animal cells: Glycogen  In plants: Starch Amylose: the unbranched type Amylopectin: the branched type

35. Branch Point in Glycogen Once in 10 units (glycogen) Once in 30 units (starch)

36. Starch and Glycogen  Starch:

37. Cellulose  One of the most abundant organic compounds in the biosphere.  The major structural polymer of plants  Consists of linear chains of glucose units

39. Glycosaminoglycans  A different kind of repeating polysaccharide is present on the animal cell surface and in the extracellular matrix.  Many glycosaminoglycans are made of disaccharides repeating units containing a derivative of an amino sugar, either glucosamine or galactosamine

40. Repeating units in Glycosaminoglycans