Polysaccharides Classification

 Polysaccharides are complex carbohydrate and are made of many monosaccharides. The bonding is called glycosidic linkage . Polysaccharides are classified on the basis of their Composition and availability/ digestivity . On the basis of their Composition, they are classified as Homo polysaccharide and Hetero polysaccharide. Homopolysaccharide are made up of only one types of monosaccharides whereas, Heteropolysaccharide are made up of more than one types of Monosaccharides. Example : starch , glycogen are homo polysaccharide while pectin , chitin are Hetero polysaccharide.

On the basis of availability, they are classified as available polysaccharide and unavailable polysaccharide. Available polysaccharide are those that can be digested by human body and provide energy example : starch , glycogen , dextrin whereas, unavailable polysaccharide are those that cannot be digested by our body as our body do not have enzyme to break it. They do not provide energy , example : cellulose , pectin, hemi - cellulose. 

SOME EXAMPLES OF POLYSACCHARIDE ARE

1. STARCH :

Starch are homo polysaccharide and are digestible . It is reserved carbohydrate in plants . Starch is made of amylose and amylopectin. They are insoluble /unsoluble in water . It is breakdown by enzyme amylase. They are found in chloroplast of plant and stored in leucoplast as granule in plant cell.

2. GLYCOGEN :

They are reserved carbohydrate in Human and Animals. It is found liver , Muscle . It is homo polysaccharide and also called Animal starch. 1/3 of glycogen is stored in liver and 2/3 is stored in muscles. 340 gram of glycogen is stored in body. It is converted to lactic acid when animal is slaughtered. It is broken down by enzyme glycogen phosphorylase

3. CELLULOSE :

Cellulose is formed of beta glycogen . It is complex oligosaccharide composed of beta glucose arranged in linear chains. They form 20-40% of plant cell wall . Cellulose are unavailable polysaccharide as human do not possessed enzyme to break cellulose. 

DIFFERENCES BETWEEN AMYLOSE AND AMYLOPECTIN 

AMYLOSE :- 

• It is linear polymer 
• Molecular weight is less
• They have good thickening power
• Capable of forming gels because of linear form

AMYLOPECTIN :-

• It is branched polymer 
• Molecular weight is four times that of amylose
• They have less thickening power
• No gel formation because of branched structure