Functions of carbohydrates

This PPT helps to simply understand the functions of carbohydrates in human health.

1. Functions of Carbohydrates Mrs.P.Ramalakshmi , M.Sc., M.Phil., Assistant Professor of Food Processing and Quality Control, V.V.Vanniaperumal College for Women, Virudhunagar .

2. Carbohydrates are sugars or polymers of sugars such as starch, that can be hydrolysed to simple sugars by the action of digestive enzymes or by heating with dilute acids. Primary fuel source for body cells Made by carbon, hydrogen and oxygen in a ratio 1:2:1 General formula CnH2nOn Carbohydrates

3. Functions of Carbohydrates

4. Functions of Carbohydrates

5. Carbohydrates are least expensive source of energy to the body. Every gram of Carbohydrate, when oxidised yields on an average 4 kilo calories. Source of Energy

6. The body uses carbohydrates as a source of energy, when they are adequately supplied in the diet, sparing protein for tissue building. If diet does not adequate calories from carbohydrate, the dietary protein is oxidised as a source of energy. There is also breakdown of tissue proteins to a greater extent. This function of carbohydrate of serving as a source of energy and preventing dietary protein from being oxidised is called Protein Sparing Action. Protein Sparing Action

7. In oxidation of fats, the acetyl CoA formed from the oxidation of fatty acids reacts with oxaloacetic acid from carbohydrate and amino acid metabolism to form citric acid which is oxidised through the TCA cycle back to oxaloacetic acid through a series of reactions. Hence, for β -oxidation of fats, carbohydrate is essential. If adequate amount of carbohydrate is not consumed, intermediary products of fat oxidation are accumulated. Acetone, acetoacetic acid and β - hydroxy butyric acid accumulate and produce ketosis. Oxidation of Fats

8. The main source of energy for central nervous system is glucose. Prolonged hypoglycemia can lead to irreversible damage to the brain tissue. Indispensability for Nervous System

9. Carbohydrates are the major source of energy for muscular work. During muscular contraction, glycogen is broken down to lactic acid through glycolysis . During the recovery period, lactic acid is first oxidised to pyruvic acid and then to acetyl CoA which is then oxidised to C02 and H2O, thus producing energy for muscular work. Role in Muscle

10. These include detoxifying action and regulating influence of protein and fat metabolism. Liver is rich in glycogen and is more resistent to certain poison such as carbon tetrachloride, alcohol, arsenic and toxins of bacteria. The rate of oxidation of amino acids in liver is diminished if abundant supply of carbohydrates are available. Role in Liver

11. The heart muscle mainly uses glucose as source of energy. In hypoglycemia , a definite adverse change in the working of the heart has been observed. Source of Energy for Heart Muscle

12. The pentose, ribose is present in RNA and in many nucleotides. It is formed in the body from glucose by Hexose Mono Phosphate pathway. Synthesis of Ribose from Glucose

13. Excess of calories fed in diet in the form of carbohydrate is stored as fat in adipose tissue. When the body is in need of energy, it can be released from the adipose tissue. Conversion to Fat

14. Lactose has several functions in the gastrointestinal tract. It promotes the growth of desirable bacteria, some of which are useful in the synthesis of B-complex vitamins. Lactose also enhances the absorption of calcium. Promotes Growth of Desirable Bacteria

15. A small amount of energy is produced from the release of short chain fatty acids in the large intestine. Fibre stimulates the peristalic movement. It helps in preventing many degenerative diseases. Contribution of Dietary Fibre

16. The carbon skeleton for the synthesis of alanine , aspartic acid and glutamic acid are provided by glucose during its oxidation, from pyruvic acid, oxalo acetic acid and β - ketoglutaric acid respectively. Biosynthesis of Amino acids

17. Carbohydrates are precursors for many organic compounds. As glycoproteins and glycolipids participate in the structure of cell membrane and cellular functions such as cell growth adhesion and fertilisation. Carbohydrates are structural components of many organisms. These include the fibre of plants, exoskeleton of some insects and cell wall of microorganisms. Structural Component