Alpha-keratin Alpha-keratin Alpha-keratin, or α-keratin, is a type of keratin found in mammals. This protein is the primary component in hairs, horns, nails and the epidermis layer of the skin. α-keratin is a fibrous structural protein, meaning it is made up of amino acids that form a repeating secondary structure. The secondary structure of α-keratin is very similar to that of a traditional protein α-helix and forms a coiled coil. Due to its tightly wound structure, it can function as one of the strongest biological materials and has various uses in mammals, from predatory claws to hair for warmth. α-keratin is
Facial hair developing facial hair, especially after menopause, though typically significantly less than men. Men may style their facial hair into beards, moustaches, goatees or sideburns; others completely shave their facial hair. The term "whiskers", when used to refer to human facial hair, indicates the hair on the chin and cheeks. The moustache forms its own stage in the development of facial hair in adolescent males. Facial hair in males does not always appear in a specific order during puberty and varies among some individuals but may follow this process: Depending on the periods and countries, facial hair was prohibited in the