Keratin Keratin Keratin () is one of a family of fibrous structural proteins. It is the key structural material making up hair, horns, claws, hooves, and the outer layer of human skin. Keratin is also the protein that protects epithelial cells from damage or stress. Keratin is extremely insoluble in water and organic solvents. Keratin monomers assemble into bundles to form intermediate filaments, which are tough and form strong unmineralized epidermal appendages found in reptiles, birds, amphibians, and mammals. The only other biological matter known to approximate the toughness of keratinized tissue is chitin. Keratin derives from Greek ' from '
Black Is the Color (of My True Love's Hair) Black Is the Color (of My True Love's Hair) "Black Is the Color (of My True Love's Hair)" (Roud 3103) is a traditional folk song first known in the US in the Appalachian Mountains but originating from Scotland, as attributed to the reference to the Clyde in the song's lyrics. The musicologist Alan Lomax supported this Scottish origin, saying that the song was an American "re-make of British materials." Many different versions of this song exist, some addressed to females and others addressed to males, as well as other differences: These words are set to two distinct melodies, one of