What fibrous protein is the main structural component of skin, hair, and nails?

What fibrous protein is the main structural component of skin, hair, and nails?

• A. Keratin
• B. Collagen
• C. Elastin
• D. Melanin

Answer: (A)

Fibrous proteins give tissues their strength and shape, and keratin is the tough, fibrous protein that forms the main structural material of hair, nails, and the outer layer of skin. In hair and nails, keratin exists as hard keratin, which is highly cross-linked and resistant to damage, giving these structures their rigidity and durability. In the skin, keratinocytes produce keratin to form a protective, waterproof barrier as they move outward and harden. Collagen, while vital for the connective tissue framework of the dermis and overall skin strength, is not the primary fibrous component of hair and nails. Elastin provides elasticity and recoil in tissues that stretch, but again it is not the main structural protein of hair, nails, or the skin surface. Melanin is pigment that determines color, not a structural protein. So, keratin best fits as the main structural protein in skin, hair, and nails.

Fibrous proteins give tissues their strength and shape, and keratin is the tough, fibrous protein that forms the main structural material of hair, nails, and the outer layer of skin. In hair and nails, keratin exists as hard keratin, which is highly cross-linked and resistant to damage, giving these structures their rigidity and durability. In the skin, keratinocytes produce keratin to form a protective, waterproof barrier as they move outward and harden.

Collagen, while vital for the connective tissue framework of the dermis and overall skin strength, is not the primary fibrous component of hair and nails. Elastin provides elasticity and recoil in tissues that stretch, but again it is not the main structural protein of hair, nails, or the skin surface. Melanin is pigment that determines color, not a structural protein. So, keratin best fits as the main structural protein in skin, hair, and nails.