keratin

American  

[ker-uh-tin] / ˈkɛr ə tɪn /

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 British  

/ ˈkɛrətɪn /

noun

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

---

keratin Scientific  

/ 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.

---

Etymology

Origin of keratin

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

Example Sentences

Researchers have found that toothpaste made from keratin, a protein naturally present in hair, skin, and wool, could both protect and repair damaged teeth while offering a sustainable alternative to traditional dental treatments.

From Science Daily

Their research revealed that keratin produces a protective coating that mimics the structure and function of natural enamel when it comes into contact with minerals in saliva.

From BBC

Their horns are made of keratin, like human fingernails, and the procedure is not thought to be painful.

From Salon

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