Question

Polysaccharide that are composed of more than one type of monomeric units are known as heteropolysaccharide.
Select the option which contains only heteropolysaccharides:

• A. Pectin, Starch & Cellulose
• B. Heparin, Agar agar & Chitin
• C. Chitin, Agar agar & Hemicellulose
• D. Heparin, Pectin, Hemicellulose

Answer 1

The correct option is D Heparin, Pectin, Hemicellulose

Pectin is a heteropolymer composed of arabinose and the sum of galactose, mannose, and galacturonic acid and it is found in the middle lamella of plant cells.

Starch is the polymer of glucose only and plants store starch as reserve food.

Cellulose is also a homopolymer of glucose and it is mainly present in plant cell walls.

Heparin has monomeric disaccharides of glucuronic acid and glucosamine in a 1,4-linkage, So it is also heteropolymer. Heparin is secreted by mast cells in blood.

Agar agar which is a heteropolymer composed of alternating galactose and glucuronic acid and it is a mucopolysaccharide present in the red algal cell wall.

Chitin is the main component of the fungi cell wall. It is a linear homopolymer of N-acetyl-D-glucosamine (NAG) monomers.

Hemicellulose is heteropolymer, made of xylose, arabinose, mannose, and galactose. It is the second most abundant carbohydrate present in plants.

So the option d is correct because heparin, pectin and hemicellulose are heteropolymers (Heteropolysaccharide).