keratin

Everyday

Keratin is a tough protein that makes up hair, nails, claws, horns, hooves, feathers and the outer layer of skin. tree →

In the lessons

A science word in lessons about the body and animals: your hair and fingernails are made of keratin, and so are a rhino's horn and a bird's feathers. It explains why cutting hair and nails does not hurt — they are made of dead keratin cells. Phrases: made of keratin, keratin protein.

Examples

• Your fingernails are made of keratin. tree →
• A rhino's horn is made of keratin, just like hair. tree →
• Feathers, claws and hooves all contain keratin. tree →
• Cutting your hair doesn't hurt because it is dead keratin. tree →
• Some shampoos say they contain keratin. tree →
• The outer layer of our skin is tough because of keratin. tree →

Note

Uncountable. Say: KERR-a-tin. Myth: a rhino horn is not made of bone or ivory, and it has no magic medicine power — it is keratin like our nails, which is why poaching rhinos is so pointless and cruel.