(Greek: containing, or derived from keratin, a highly insoluble scleroprotein that is the main constituent of horny tissues, the nails, and the organic matrix of tooth enamel; derived from Greek kera[s], kerat[os], "horn")
Included are the cytokeratins of epithelial tissue and the hard keratins of ectodermally derived structures; such as, hair and nails.
Because it is insoluble in gastric juice, keratin is sometimes used to coat pills designed to dissolve in the intestine.
Leather is almost pure keratin.
2. A process occurring in vertebrate epidermis and epidermal structures in which keratin replaces the cytoplasm of a cell.
An example of keratinization is the cornified outer layer of the epidermis of the skin that consists of dead horny cells.
Hairs and finger-toe nails also consist of keratinized cells.
2. A pill or tablet having keratin as an enteric coating.