Question

The protein present in hair is:
A.Lysine
B.Myosin
C.Keratin
D.Alanine

Answer 1

Hint: Proteins are nitrogenous compounds having large molecules that are composed of long chains of amino acids. Proteins are essential for all living organisms. Hair strands are fibrous in nature. This is because hair contains fibrous protein.

Complete step by step answer:
Hair grows out of hair bulbs. The hair bulbs are follicles that are located in the junction between the deep layer of dermis and the hypodermis.
Blood is supplied to the hair bulbs by a small vessel passing through the inner side of the hair bulb. This provides hair with all the vital elements such as amino acid, vitamins and mineral salts.
The hair bulb is surrounded by the sebaceous gland. The sebaceous gland provides hair with sebum. The sebum acts as a natural lubricant for the hair.
The hair is made up of a fibrous and helicoidal protein called keratin. 95% of hair is made up of keratin.
The protein keratin is insoluble in water. It is synthesized by keratinocytes. Keratin is rich in a sulfated amino acid cysteine. Cysteine forms disulfide bonds between the molecules and adds to the rigidity and resistance of the structure.
Hair consists of eighteen other amino acids like proline, threonine, leucine and arginine.
Thus, the protein present in hair is keratin.
Thus, the correct option is option (C).

Note:
Keratin is a fibrous protein and it functions as a biological structural material. Keratin consists of a mixture of peptides with high and low cysteine content.