Carbohydrates are classified as monosaccharides oligosaccharides and polysaccharides.
(1) Monosaccharides :
These carbohydrates cannot be further hydrolysed into smaller units.
They are basic units of all carbohydrates, and are called monosaccharides.
Examples :
Glucose, fructose, ribose
(2) Oligosaccharides :
An oligosaccharide is a carbohydrate (sugar) which on hydrolysis gives two to ten monosaccharide units.
Depending on the number of monosaccharides produced on hydrolysis, oligosaccharides are further classified as :
(1) Disaccharides (C12H22O11) :
(2) Trisaccharides (C18H32O16) :
(3) Tetrasaccharides (C24H42O21) :
Oligosaccharide is homogeneous. In this, each molecule of oligosaccharide contains the same number of monosaccharide units joined together in the same order as every other molecule of the same oligosaccharide.
(3) Polysaccharides :
These are carbohydrates which on hydrolysis give a large number of monosaccharides.
Polysaccharides are tasteless, amorphous, insoluble in water.
They are long chain, naturally αcurring polymers of carbohydrates.
Example :
Cellulose, starch, glycogen.
