What is the name of the fiber protein found in nails, skin, and hair?

The fiber protein found in nails, skin, and hair is called keratin. Keratin is a structural protein that plays a crucial role in providing strength and protection. It is a key component of the outer layer of skin (epidermis), forms the tough characteristics of hair, and gives nails their hard structure. Keratin helps to form a barrier that protects underlying tissues from damage and dehydration.

In contrast, melanocytes are cells that produce melanin, the pigment responsible for the color of skin and hair, but they do not contribute as a fibrous protein. Keratoma refers to a type of growth or tumor of the skin that results from an overproduction of keratin and does not describe the protein itself. Keratinin is not a recognized term in this context; the correct term is keratin. Understanding these distinctions clarifies why keratin is the sole answer related to the composition of nails, skin, and hair.