Keratin facts for kids
Keratins are a group of strong, fibrous proteins. Think of them as tiny, tough building blocks! They are super important because they make up many hard parts of animals. For example, your hair and nails are mostly made of keratin.
Animals like mammals, birds, and reptiles use keratin for many things. It forms horns, hooves, beaks, and feathers. The word "keratin" comes from the Greek word keras, which means "horn."
Keratins are very tough and do not dissolve in water. They create hard structures that are not made of minerals. This is different from bones or teeth, which do contain minerals. You can find similar tough materials like chitin in other parts of the animal world.
What Keratins Do for Animals
Keratins are the main material for many parts that grow from an animal's skin. There are two main types:
- The α-keratins are found in mammals. They make up soft things like hair (including wool), and harder parts like horns, nails, claws, and hooves.
- The β-keratins are even harder. They are found in reptiles and birds. These keratins make up the scales and claws of reptiles. They also form the shells of animals like tortoises and turtles. In birds, β-keratins make up their feathers, beaks, and claws.
Even tiny arthropods like crustaceans use keratin. Parts of their outer shell, called an exoskeleton, are often made of keratin. Sometimes it is mixed with chitin.
Keratins are also found inside many animals. For example, roundworms have keratin in their digestive system. Their outer layer is also made of keratin.
Scientists believe that the scales, claws, and beaks of dinosaurs were also made of a type of keratin. This would have given them tough, protective armor.
Keratin and Silk
The silk fibroins made by insects and spiders are sometimes called keratins. However, it is not clear if they are related to the keratins found in animals with backbones.
Silk found in insect pupae, and in spider webs, is very strong. It has special twisted structures that make the fibers tough.
Images for kids
See also
In Spanish: Queratina para niños
