BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Keratin exists in different forms like -keratin and -keratin. -Keratin is usually found in soft tissues like sheep wool, skin, and hair, while -keratin is found in hard tissues like bird feathers, horns, claws, and hooves [77].

Detailed explanation-2: -A type of protein found on epithelial cells, which line the inside and outside surfaces of the body. Keratins help form the tissues of the hair, nails, and the outer layer of the skin. They are also found on cells in the lining of organs, glands, and other parts of the body.

Detailed explanation-3: -Keratin is a fibrous structural protein found in animal cells and used to form specialized tissues. Specifically, the proteins are only produced by chordates (vertebrates, Amphioxus, and urochordates), which includes mammals, birds, fish, reptiles, and amphibians.

Detailed explanation-4: -Alpha-keratins (-keratins) are found in all vertebrates. They form the hair (including wool), the outer layer of skin, horns, nails, claws and hooves of mammals, and the slime threads of hagfish. The baleen plates of filter-feeding whales are also made of keratin.

Detailed explanation-5: -Keratins are expressed in all types of epithelial cells (simple, stratified, keratinized and cornified) (Moll et al., 1982; Bragulla and Homberger, 2009).