Question

Amylose and amylopectin chains occur in
A. Glycogen
B. Starch
C. Cellulose
D. Chitin

Answer 1

Hint: It is a glucose-based storage polysaccharide. This molecule consists of a simple amylose chain and an amylopectin branch chain.

Complete Answer:
- Amylose is composed of a linear helical chain of around 500 to 20,000 monomers of alpha-D-glucose connected by alpha glycosidic bonds (1-4). Amylopectin molecules, each containing between 1 and two million of residues, are massive, branched glucose polymers. Amylopectin is branched in relation to amylose.
- Glycogen is a ramified glucose polymer. Glucose residues are bound linearly by alpha 1,4 glycosidic links, while a chain of glycoside residues is broken down by alpha 1,6 glycosidic links roughly every ten residues. A helical polymer structure is formed by the alpha glycosidic bonds.
- Starch is a glucose-based storage polysaccharide. A starch molecule consists of a simple amylose chain and an amylopectin branch chain. Amylose is formed by alpha 1, 4 linkage in a straight chain of glucose molecules. Glucose units are bound to glycoside bonds in Amylopectin in a linear manner and branches occur per 24 to 30 glucose units with (16) bonds.
- Cellulose is composed of long chains of d-glucose units connected with beta glycosidic (shaded) bonds and alternating units revolving about 180° from the surrounding area. This indicates that the repeated unit is a straight chain rather than glucose.
- Chitin is a glucose-derivative long-chain polymer called N-acetyl-glucosamine. Chitin is a nitrogen-containing modified polysaccharide; it is composed of N-acetyl-D-glucosamine units. Therefore, on each monomer substituted by a group of acetyl amine chitin can be represented as cellulose with a hydroxyl group.

Thus, the correct answer is B. i.e., Starch.

Note: Amylose is composed of a linear helical chain of around 500 to 20,000 monomers of alpha-D-glucose connected by alpha glycosidic bonds (1-4). Amylopectin molecules, each containing between 1 and two million of residues, are massive, branched glucose polymers.