Question Bank [2022] — Chemistry STD 12 Science — Question

Classification of carbohydrates: Carbohydrates are classified into three broad groups in accordance with their behaviour on hydrolysis as monosaccharides, oligosaccharides, and polysaccharides.

1. Monosaccharides: Monosaccharides are carbohydrates which do not hydrolyse further into smaller units of polyhydroxy aldehydes or ketones.
   e.g. Glucose, fructose, ribose
2. Oligosaccharides: Oligosaccharides are carbohydrates which on hydrolysis yield two to ten units of monosaccharides and accordingly they are further classified as disaccharides, trisaccharides, and so on.
   a. Disaccharides yield two monosaccharide units on hydrolysis.
   e.g. Sucrose
   b. Trisaccharides yield three monosaccharide units on hydrolysis.
   e.g. Raffinose
   c. Tetrasaccharides yield four monosaccharide units on hydrolysis.
   e.g. Stachyose
3. Polysaccharides: Polysaccharides give very large number of monosaccharide units on complete hydrolysis.
   e.g. Starch, glycogen, cellulose