Question

Explain the biological importance of proteins.

Answer 1

The biological importance of proteins are :
(1) Fibrous protein keratin forms external protective structures of animals like nails, hooks, scales, hair, feathers, horny layer of skin etc.
(2) Immunoglobins or antibodies are proteins produced by lymphocytes. They are meant for recognizing and neutralizing foreign proteins, toxins, viruses and other pathogens.
(3) They are both defensive and offensive proteins produced by certain animals, bacteria and some plants, e.g., Snake venom.
(4) Proteins constitute more than 50% of the dry weight of protoplast. They take part in formation of colloidal complex ofprotoplast, cell organelles, cell membranes and cell products.
(5) Pollen grains possess specific proteins in their walls for compatibility incompatibility reaction with the stigma during pollination.
(6) Some hormones are proteinaceous, e.g., insulin, growth, hormone of pituitary etc.
(7) Fibrinogen and thrombin prevent blood loss from injured vessels by causing clothing of blood.
(8) Antibodies are formed of proteins.