CARBOHYDRATE

1. CARBOHYDRATE

2. The energy cycle of life

3. Introduction • Saccharide is another name for a carbohydrate. • Simple saccharides are the monosaccharides, commonly called sugars. Glucose is an example of a monosaccharide. • Many carbohydrates have a formula that can be simplified to (CH2O)n. • We use the terms monosaccharide, oligosaccharide, or polysaccharide to refer to compounds composed of a single sugar, several sugars linked together, or many sugars linked together, respectively. • Saccharides play a variety of roles in living organisms, including energy storage (monosaccharides and oligosaccharides), structural roles (polysaccharides)

4. Classification of Carbohydrates • Monosaccharide or Simple Sugar • Complex Carbohydrate • Oligosaccharide • Polysaccharide

5. Monosaccharides • Monosaccharides are the simplest sugars, having the formula (CH2O)n. The smallest molecules usually considered to be monosaccharides are those with n = 3. • Monosaccharides can be categorized according to their value of 'n‘ • Monosaccharides can exist as aldehydes or ketones and are called aldoses or ketoses, respectively. • Monosaccharides can form five or six membered ringsand are called furanoses and pyranoses, respectively.

6. Trioses, the simplest monosaccharides

7. Fischer projection

8. Stereochemical relationships of the D- aldoses

9. Stereochemical relationships of the D-ketoses.

10. Formation of ring structures

11. Haworth projection -D-glucopyranose Haworthprojection -D-glucopyranose Fischerprojection

12. Conformation chair form boat form chair form

13. -D-glucopyranose Haworthprojection conformation Fischerprojection

14. Anomers

15. Mutarotation

16. Oligosaccharides • Glycosidic bonds between monosaccharides give rise to oligosaccharides and polysaccharides. • The simplest oligosaccharides, the disaccharides, include compounds such as sucrose and lactose, which are referred to as sugars (like the monosaccharides). • Other common disaccharides include trehalose, maltose, gentiobiose, and cellobiose

17. Four features distinguish disaccharides from each other: 1. The two specific sugar monomers and their stereoconfigurations 2. The carbons involved in the linkage 3. The order of the monomeric units, if they are different kinds 4. The anomeric configuration of the hydroxyl group on carbon 1 of each residue

18. Formation of lactose

22. Polysaccharides • Polysaccharides are polymers of monosaccharide units. • The monomeric units of a polysaccharide are usually all the same (called homopolysaccharides), though there are exceptions (called heteropolysaccharides). • Polysaccharides are used to some extent for energy storage in almost all higher organisms. Animals use glycogen. Plants use starch, which is composed of amylose and amylopectin. In both plants and animals, the polysaccharides used for energy storage are readily broken down into monomeric units that can be rapily metabolized to produce ATP. In addition to polysaccharides used for energy storage, plants use different polysaccharides, such as cellulose, for structural purposes in their cell walls. The exoskeleton of many arthropods and mollusks is composed of chitin, a polysaccharide of N-acetyl-D-glucosamine.

24. Common polymers, their monomeric units, and linkages/branches are shown below: Polysaccharide Monomeric Unit Linkages Name Glycogen D-Glucose 1->6 branches Cellulose D-Glucose 1->4 ChitinN-Acetyl-D-glucosamine 1->4 Amylopectin D-Glucose 1->6 branches Amylose D-Glucose 1->4

25. Starch

26. Amylose

27. Amylopectin

28. Celluloses

29. Organization of plant cell walls