Carbohydrate metabolism

Types of Carbohydrates, function and importance

1. Tridip Boruah Assistant Professor Department of Botany M.C College, Barpeta Carbohydrate Metabolism

2. Carbohydrates are polyhydroxy aldehydes or ketones and their condensation products. Dependending on the presence of numbers of saccharides unit, they can be classified. Mainly they are classified into Monosaccharides Oligosaccharides Polysaccharides Carbohydrates

3. Structure of Monosaccharides Empirical formula: ( CH 2 O) n n= 3: Triose n=4: Tetrose n =5: Pentose n=6: Hexose N=7: Heptose

4. Biological importance of monosaccharides Role in photosynthesis As fuel of the physiological processes Component of nucleic acids Building blocks of complex biopolymers Act as intermediate between different complex metabolic pathways

5. Disaccharides Two monosaccharide units connected by a glycosidic bond (C1-> C4) Sucrose: Glucose + Fructose

6. Maltose= Glucose + Glucose

7. Lactose= Galactose + Glucose

8. Polysaccharides These are complex long chain carbohydrates which are formed by polymerisation of more than ten but generally very large number of units of monosaccharides . On the basis of structure i) Homopolysaccharides : Starch, Cellulose ii) Heteropolysaccharides : Pectin, Hemicellulose

9. 2) On the basis of function Storage Polysaccharides : Functions as reserve food material, required for respiration and biosynthesis Starch, Glycogen, Insulin ii) Structural polysaccharides : Fibrous in nature, required in the formation of cell wall, exoskeletons Cellulose, Chitin iii) Mucopolysaccharides : High molecular weight compounds, gelatenous in nature, required for lubrication Agar agar , Pectin, Heparin