keratin

American

[ker-uh-tin] / ˈkɛr ə tɪn /

noun

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

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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

keratin Scientific

/ kĕr′ə-tĭn /

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

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The texture of the crest and the network of blood vessel channels inside it indicate that it was covered in keratin, the same material found in human fingernails.

From Science Daily

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

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023