Question

Polymer of $\alpha -D$ glucose is
(a) Cellulose
(b) Glycogen
(c) Insulin
(d) Chitin

Answer 1

Hint: Those materials which are made up of long and repeated chains of glucose molecules are known as polymers of glucose. This polymer is found only in animals and is also called' animal starch'. It serves as energy storage in animals.

Complete answer:
A polymer of $\alpha -D$ glucose as glycogen. It is found in the form of granules in the cytoplasm of the cells, and it plays a vital role in the glucose cycle. It is a long chain of linked glucose molecules that is a polymer of alpha(1-4) glycosidic bonds.
-To nourish the embryo the glycogen is stored in the uterus during the pregnancy.
-Glycogen is insoluble in water and can turn brown-red when mixed with iodine.
-In the hydrolysis of glycogen, glucose is produced.
-Chitin forms the hard part of the exoskeleton in crustaceans and insects such as cockroaches. It is also a long-chain polymer and the main component of the cell walls of fungi.
-Cellulose is the most profuse organic polymer present on our Earth. It is found mainly in plants. Some species of bacteria such as Acetobacter, Azotobacter, and Rhizobium secrete it to form biofilms.
-These units are joined by a glycosidic bond. This polysaccharide is mostly produced by green plants for energy storage, e.g. potatoes.
-Beta cells of the pancreatic islets produce the peptide hormone insulin. It is said to be the main anabolic hormone of the body as it regulates the metabolism of carbohydrates, fats, and proteins.

So, the correct answer is ‘Glycogen’.

Note:
-Glycogen is stored in the form of energy in the liver and muscles of animals.
-It is a multi-branched polysaccharide of glucose. It is also found in some fungi as stored energy.
-Starch is a carbohydrate consisting of a long chain of glucose units.