Question

What is keratin?
A. Fibrous proteins
B. Characteristics of rhinoceros horn
C. Selenoproteins
D. All of the above

Answer 1

Hint: Keratin is one of an intimate of tough structure proteins identified as scleroproteins. Hair strands are also fibrous. Protein structure refers to a condensation of amino acids which forms peptide bonds.

Complete answer:
> Hair grows out of follicles located in the junction between the deep layer of dermis and the hypodermis. These follicles are also known as hair bulbs. Blood flow is complete by a small basin that permits through the secret of the hair slide, thus providing the hair with all the vigorous fundamentals it wants to remain healthy such as amino acid, minerals, salts and vitamins.

> The hair shaft is surrounded by glands, the most important being the sebaceous gland, which provides sebum that acts as natural lubricant for the hair. The hair is prepared up of 95% keratin, stuff, helicoidal protein that systems the shares of the membrane. It also makes up nails.

> Keratin is synthesized by keratinocytes and is insoluble in water, thus ensuring impermeability and protein for the hair.

> Some 18 amino acids can be found in hair such as proline, threonine, leucine, and arginine. Keratin is mainly rich in cysteine, a type of sulphurated amino acid which procedures disulfide bond amongst particles, count inflexibility and conflict to the complete organization.

Hence, the correct answer is option (D).

Note: Keratin functions as biological structure material and is an example of fibrous protein. It is also the outer layer of human skin. The most carefully examined keratin is the fur keratin, mostly that of yarn.