What are proteins? Give important functions of proteins in living organism.

Explanation

Proteins are the polymers of about twenty different `alpha`-amino acids which are linked by peptide bonds.
Functions :
(i) Proteins are one of the main constituent of protoplasma of plant and animal cell.
(ii) As enzymes, they catalysc biochemical reactions.
(iii) As hormones, they regulate metabolic processes.
(iv) As Antibodies, they protect the body against toxic substances.