1. Chapter 18 Carbohydrates

2. Goals Distinguish and describe mono, di, oligo, and polysaccharides Classify and name monosaccharides Know D aldose and ketose Draw cyclic hemiacetals Describe photosynthesis Know mutarotation, oxidation, acetal formation

3. Beginning of Biochemistry Biomolecules – 3 aspects to consider

4. Biomolecules Four main families –Carbohydrates –Nucleic acids

5. Carbohydrates Called saccharides Functions

6. Where found Sugar Wood

7. Classifications Polyhydroxyketone (ketose) Monosaccharides

8. Naming IUPAC is not used… long and difficult names Most names are common names and end in

9. Structure Aldose Ketose

10. Classifying 5 carbon with aldehyde group 4 carbon with a ketone group See figures 18.1 and 18.2 p 528-9

11. D or L? Chiral recognition and the use of enzymes in organisms selectively produces the D form of the –ose L form is not produced in nature

12. Important monosaccharides D-Glucose D-Fructose D-Galactose

13. Monosaccharides D-Ribose D-Xylose D-glyderaldehyde and D-hydroxyacetone

14. Cyclic Hemiacetals Presence of both carbonyl carbon and hydroxyl group allows for cyclic structure The closed ring is called a Page 531

15. Cyclic hemiacetals Unlike straight chain hemiacetals, cyclics are Isomeric difference is important for function

16. Cyclics Ketohexoses form –Addition of an –OH to C5 –Two anomers are formed Haworth projections (figures 18.3 and18.4)

17. Mutarotation All aqueous solutions of D-glucose Isolate alpha and make a solution, after time the mixture Same process for each anomer Mutarotation is change in specific rotation of light to the equilibrium value

18. Oxidation of aldose Oxidation of open structure, not hemiacetal Governed by

19. Oxidation Alpha-hydroxy ketones Aldoses and ketoses are called “Reducing Sugars” –Reduce Cu 2+ to Cu +

20. Glycosides Formation of an acetal –Page 537 –Alpha and beta glycosides depending on which anomer is converted –In organisms,

21. Glycosides Acetals of carbos are Carbons are connected by a glycosidic linkage. Two types: – Nature is stereospecific – This bond forms di and polysaccharides

22. Monosaccharide derivatives

23. Disaccharides Two monosaccharides connected with glycosidic linkage Characterized by:

24. Four Important Maltose: Cellobiose: Lactose: Sucrose:

25. Digestion of Carbohydrates Large saccharides They must be broken down

26. Polysaccharides Large numbers of monosaccharide residues

27. Polysaccharides Differ from each other in many ways

28. Starch Amylose: Amylopectin: branched D-glucose Glycogen:

29. Digestion of Starch Digested to D-glucose in intestines by amylase Neither Dextrin is digested by

30. Starch Digestion Some Some polymerized Extra glucose (beyond needed) When needed,

31. Cellulose Structural polysaccharide Most abundant organic compound in biosphere Cotton is nearly pure cellulose Linear polyglucose: B(1-4) linkages

32. Starch and Cellulose A(1-4) Add water? Food for humans Links not allow for extended conformations Form helices fig 18.14 B(1-4) Add water? Not good food Links allow for extended 3D conformations Fig 18.13 p 547

33. Cellulose - uses Build houses Fabrics – Paper Starting point

34. Cell recognition Process that ensures cells interact as they should within the organism Due to presence of Usually

35. Photosynthesis Source of energy for non-plant life and all organic molecules used Process of carbon fixation

36. Photosynthesis Plants convert glucose and other monosaccharides to: