Carbohydrates

1. Carbohydrates Carbohydrates • Are produced by photosynthesis in plants. • Such as glucose are synthesized in plants from CO2, H2O, and energy from the sun. • Are oxidized in living cells (respiration) to produce CO2, H2O, and energy.

2. Types of Carbohydrates The types of carbohydrates are • Monosaccharides, the simplest carbohydrates. • Disaccharides, which consist of two monosaccharides. • Polysaccharides, which contain many monosaccharides.

3. Classification of Monosaccharides Aldoses Aldoses are monosaccharides • With an aldehyde group. • With many hydroxyl (─OH) groups. triose (3 C atoms) tetrose (4 C atoms) pentose (5 C atoms) hexose (6 C atoms) O ║ C─Haldose │ H─ C─OH │ H─ C─OH │ CH2OH Erythrose, an aldotetrose

4. Classification of Monosaccharides Ketoses Ketoses are monosaccharides • With a ketone group. • With many hydroxyl (─OH) groups. triose (3 C atoms) tetrose (4 C atoms) pentose (5 C atoms) hexose (6 C atoms) CH2OH │ C=O ketose │ H─ C─OH │ H─ C─OH │ H─C─OH │ CH2OH Fructose, a ketohexose

5. Fischer Projections A Fischer projection • Is used to represent carbohydrates. • Places the most oxidized group at the top. • Shows chiral carbons as the intersection of vertical and horizontal lines. • The groups to the left and right are pointed out toward you and the groups top and bottom are pointed away from you.

6. D and L Notations In a Fischer projection, the −OH group on the • Chiral carbon farthest from the carbonyl group determines an L or D isomer. • Left is assigned the letter Lfor the L-isomer. • Right is assigned the letter Dfor the D-isomer.

7. Pentoses Monosaccharides: Trioses and Pentoses Trioses

8. Monosaccharides: Hexoses

9. Summary of the Formation of Cyclic Glucose

10. Cyclic Forms of Monosaccharides

11. Disaccharides

13. Sucrose

14. Polysaccharides Starch

15. Linkage in Amylose

16. Amylose Structure

17. amylopectin

19. Linkage in Cellulose

20. Cellulose Structure

21. Bacterial Cell Wall