When at least 10 or more monosaccharides are linked together (possibly up to an infinite number), they form “glycosidic bonds.” This structure is known as a polysaccharide.
Major Types of Polysaccharides:
- Cellulose
- Starch
- Glycogen
- Chitin
- Dextrin
- Pectin
- Cellulose
Cellulose is useful for all three essentials of life: food, clothing, and shelter.
Cotton contains 92% cellulose. It is used to make cotton fabrics.
Cellulose forms the plant cell wall. The structure and build of all trees and plants are made possible by cellulose.
- Cellulose is a structural carbohydrate.
- It is the most abundantly found carbohydrate on Earth.
- It is present in sugarcane residue (bagasse).
Uses:
Cellulose is used in making paper, currency notes, and sanitary pads.
- Starch
Starch is a polysaccharide found in food.
When it is cooked or boiled, its volume increases.
Capsule shells (used in medicines) are made using starch.
Digestion of Starch:
The digestion of starch begins in the oral cavity itself.
An enzyme called ptyalin (from saliva) is responsible for this.
- Glycogen
Glycogen is also called an animal carbohydrate
because it accumulates in the liver and muscles.
It is known as a stored fuel because when required, glycogen converts into glucose.
- Chitin
Chitin is also a structural carbohydrate.
It is found on the outer surfaces of insects.
Example: Cockroach.
The cell wall of fungi is made of chitin.
- Dextrin
Dextrin is found in roasted rice and bread.
During digestion, dextrin combines with the ptyalin enzyme in saliva and converts into fructose.
Due to the presence of fructose, we get a slightly sweet taste when chewing bread.
Fructose is the sweetest sugar.
- Pectin
Pectin acts as a cementing agent that helps plant cells stick together.
Due to this, plants become firm and strong.
