Carbohydrates : function source and Classification

Carbohydrates : function source and Classification :- Carbohydrates are the most abundant of all the organic compound in nature The Carbohydrates composed of carbon, hydrogen and oxygen. The word Carbohydrates means hydrates of carbon. Defined as polyhydroxy-aldehydes or ketones or composed which produce tem on hydrolysis.

Carbohydrates : function source and Classification
Carbohydrates : function source and Classification

Function of Carbohydrates

  1. they are the main constituent of diet.
  2. They are the main source of energy.
  3. They are essential for the oxidation of fats.

Source of Carbohydrates

  1. Sugar
  2. starch
  3. Cellulose

Sugar :- They are the simplest form of Carbohydrates

Starch:- It is polysaccharides. It form the basic human diet

Cellulose :- It is the indigetible constituents of carbohydrates.

Classification of Carbohydrates

  1. Monosaccharides – simple sugar
  2. Disaccharides – sucrose, maltose
  3. Oligosaccharides – Reffinose, stachyose
  4. Polysaccharides – Starch , glycogen.


monosaccharide are the simple sugar or compounds which posses a free aldehyde (CHO) or ketone (C=O) group and two or more hydroxyl (OH) groups.

They are the simplest sugars and cannot be hydrolyzed further into smaller unit. Monosaccharide contain a single carbon chain and are classified carbon atoms they possoes and as Aldo’s or ketoses depending upon their groups.


The disaccharides are sugar composed of two monosaccharide Residue linked by a glycosidic bond. The disaccharide of physiological importance are as follow.

  • Maltose
  • Isomaltose
  • Sucrose
  • Lactose
  • Lactulose
  • Trchalose


Trisaccharide : Raffinose ( Galactose+Galactose+fructose)

Tetrasaccharide : stachyose (2Galactose+Glucose+fructose)

Pentasaccharide : Verbascose (3Galactose+glucose+fructose)

Hexasaccharide : Ajugose ( 4 Galactose+Glucose+fructose)


Homoglycons ( starch, cellulose, glycogen, sections or insulin)

Hetroglycans ( Mucopolysaccharides)


  • Polymer ( MW form 200000)
  • White and amorphous products ( glassy)
  • Not sweet
  • Not reducing
  • Form colloidal solution or suspension