Question

The fibrous protein is/are?
A. Keratin
B. Myosin
C. Elastin
D. All

Answer 1

Hint: Polypeptide chains that are elongated and fibrous or have a sheet-like shape makeup fibrous proteins. These fibres and sheets are water-insoluble and mechanically robust. They're usually structural proteins that give cells and tissues their strength and protection. Because the polypeptide chains in the beta-pleated sheets are already stretched out, they are robust and somewhat inextensible, making them well suited to this task.

Complete answer:
Option A: Keratin is a fibrous protein found in hair, horns, skin, claws, and hooves as a structural material. It's a fibrous structural protein in which the keratin monomers create an alpha helix keratin, meaning the keratin protein is made up of amino acids that form a secondary structure. and coil into a coiled-coil.
Hence, option A is correct.
Option B: Myosin is a motor protein that helps muscles move. It is found in the muscles of the body. The contraction of the muscle is achieved by the function of myosin.
Hence, option B is incorrect.
Option C: Elastin is an important extracellular matrix protein. It is very elastic and found in connective tissue, allowing many tissues in the body to return to their original shape after being stretched or contracted. When skin is poked or pinched, elastin helps it return to its normal place.
As a result, option C is incorrect.
Option D: Since it is proven that the option b and c are incorrect. All of the above cannot be the correct option.
Hence, option D is incorrect.

Hence, Option A is the correct answer.

Note:
The keratin helix is very tightly bonded, and this structure gives the protein its strength, which is why it is found in animal features such as claws and hooves that aid in the capture of prey. Keratin also helps to protect epithelial cells from harm and stress. In both water and organic solvents, keratin is very insoluble. Keratin monomers bundle into intermediate filaments, which are tough and create robust unmineralized epidermal appendages in reptiles, birds, amphibians, and mammals.