keratin

[ ker-uh-tin ]

noun

1. a fibrous, structural protein that is the principal constituent of hoofs, nails, claws, talons, bills, horn, hair, feathers, etc., and that is found in the outermost layers of skin.

keratin

/ ˈkɛrətɪn /

noun

1. a fibrous protein that occurs in the outer layer of the skin and in hair, nails, feathers, hooves, etc

keratin

/ kĕr′ə-tĭn /

1. Any of a class of tough, fibrous proteins that are the main structural component of hair, nails, horns, feathers, and hooves. Keratins are rich in sulfur-containing amino acids, especially cysteine. Individual keratin molecules are entwined helically around each other in long filaments, which are cross-linked by bonds between sulfur atoms on different chains. The twining and cross-linking produce strength and toughness.

Word History and Origins

Origin of keratin¹

First recorded in 1840–50; kerat- + -in ²

Example Sentences

Like the blue whale, fin whales are balleens, sporting two blowholes and, instead of teeth, hundreds of rows of baleen plates made of keratin.

From Los Angeles Times

In an exploratory operation, doctors at St George's found keratosis - lesions or white patches on the vocal chords in Tyler's throat - due to the growth of the protein keratin, usually found in skin and hair.

From BBC

Given that keratin is a primary constituent of hair and skin, its application as a hair growth agent is assumed to be safe and effective, with negligible adverse effects.

From Science Daily

Using a simple and environmentally friendly process, they extract the protein keratin from the feathers and convert it into ultra-fine fibres known as amyloid fibrils.

From Science Daily

Their most distinctive feature, the horn, is composed of keratin, the same substance found in human hair and nails.

From Salon