These are organic compounds formed of carbon, hydrogen and oxygen consists more than one alcoholic group in which the ratio of hydrogen and oxygen is 2:1. It is also called hydrates of carbon because there is one water molecule for every carbon because there is one water molecule for every carbon atom. The simplest form of carbohydrates is called monosaccharide which cannot be hydrolised further such as glucose, fructose, etc. The combination of 2 to 10 monosaccharide by glycositic bond forms oligosaccharides. The well known oligosaccharides are disaccharide formed of combination of two monosaccharide such as maltose, lactose etc. The combination of more than 10 monosaccharides forms polysaccharides such as starch, glycogen etc.

Sources:

Rice, wheat, potato, honey, bread, etc.

Daily requirement:

A healthy adult person requires 500 gm carbohydrates per day. This requirement becomes more for those individuals who work hard in the field. The consumption of more for those individual who works hard in the field.  The consumption of more carbohydrates cause its conversion into glycogen for storage. It is also converted into fats and stored in adipose tissue.

Function:

i) It is basic source of energy because it contains more oxygen. So, required less oxygen for its oxidation to release energy. Thus, it is energy giving nutrient .About 70% of total energy requirement is fulfilled from carbohydrates. The physiological value of one gm of carbohydrates is 4 kilo calorie while energy or calorie present is about 4.1 kilo calorie.

ii) It acts as stored food. The excess glucose is converted into glycogen in the liver and stored in the liver and muscles.

iii) It helps in protein synthesis by converting itself into amino acid.

Iv) It acts as structural components as it forms nucleic acid and cell membrane.

v) In the form of heparin, it prevents the clotting of blood in the blood vessels.

VI) In the form of antigen A and antigen B, it determines the blood group of an individual.