Biology - Carbohydrate


  • Consisting of oxygen (O), carbon (C), and hydrogen (H), carbohydrate is a biological molecule.

  • Carbohydrate is one of the essential elements for the living organisms, as it plays various important roles.

  • Carbohydrate is the main source of energy, as about two-third energy requirement of living beings is fulfilled by it.

  • Glucose, sugar, and starch are the important examples of carbohydrate.

Source of Carbohydrate

  • Carbohydrates naturally are occurring in wide variety of foods, such as −

    • Wheat

    • Maize

    • Rice

    • Potatoes

    • Sugarcane

    • Fruits

    • Table sugar

    • Bread

    • Milk

  • Sugar that we eat in our everyday life is mainly sucrose (table sugar).

  • Sucrose is added in many food items while preparing, e.g. jam, biscuits, cakes, energy drinks, etc.

  • Further, many fruits naturally contain glucose and fructose.

  • Glycogen is another type of carbohydrate that found in the liver and muscle.

  • Cellulose found in the cell wall of plant cells is carbohydrate.

Types of Carbohydrate

  • The following table illustrates major categories and sub-categories of carbohydrate −

Class Subgroup Components
Sugar Monosaccharides Glucose, fructose, xylose, galactose
Disaccharides Sucrose, lactose, maltose, trehalose
Polyols Sorbitol, mannitol
Oligosaccharides Malto-oligosaccharides Maltodextrins
Other oligosaccharides Raffinose, stachyose, fructo-oligosaccharides
Polysaccharides Starch Amylose, amylopectin, modified starches
Non-starch polysaccharides Cellulose, hemicellulose, pectins, hydrocolloids

Functions of Carbohydrate

  • Following are the major functions of carbohydrates −

    • Carbohydrates provide energy required for the proper function of the body.

    • Carbohydrates also store food in the body for the contingency period.

    • Carbohydrates form nucleic acids.

    • Carbohydrates also support skeleton system of animals.

    • Carbohydrates provide sweetness and flavor.

    • Carbohydrates break down the fatty acid.