Dictionary > Keratin

Keratin

Definition
noun, plural: keratins
One of the fibrous structural proteins, and is a constituent of hair, nails, skin, feathers, hooves, horns, etc.
Supplement
Scleroproteins or the fibrous proteins are one of the three major types of proteins; the other two are spheroproteins and membrane proteins. Scleroproteins are characterized by their long protein filaments. They act as structural proteins. They are usually water-insoluble. Some of the scleroproteins are keratin, collagen, elastin, and fibroin.
Keratins are fibrous structural proteins that constitute various biological structures such as hair, nails, skin, feathers, hooves, horns, etc. They are made up of coiled polypeptide chains and when they combine they form supercoils.
Keratins protect epithelial cells from damage. Skin cells that are constantly exposed to pressure and rubbing leads to the formation of calluses. The skin thickens and the epidermal cells undergo cornification. Cornification is a process in which a keratinized layer of epidermis forms and serves as an epidermal barrier. During cornification, keratin fills up the cell resulting in the loss of cytoplasmic organelles and the cessation of metabolism. Ultimately, the fully keratinized cells undergo a programmed cell death.
Word origin: Greek keras (horn) + –in
See also:

Related term(s):

  • keratinization
  • Related form(s):

    • keratinous (adjective, relating to keratin; horny)


    You will also like...

    New Zealand Flora & Fauna
    Ecology & Biodiversity: New Zealand Flora & Fauna

    New Zealand is known for its unique biodiversity, caused by its remarkable geography and geologic history. Breaking away..

    Kidneys
    Kidneys and Regulation of Water and Inorganic Ions

    The kidneys are responsible for the regulation of water and inorganic ions. Read this tutorial to learn about the differ..

    A sperm cell fertilizing an ovum
    Human Reproduction and Fertilization

    For human species to obviate extinction, reproductive mature adults should be producing viable offspring in order to con..

    Direct and indirect physiologic effects of growth hormone
    Animal Growth Hormones

    Hormones are produced in the endocrine glands of animals. The pituitary gland and hypothalamus are the most impor..

    DNA - schematic
    Genetic Mutations

    This tutorial looks at the mutation at the gene level and the harm it may bring. Learn about single nucleotide polymorph..

    Neurology of Illusions
    Neurology of Illusions

    Illusions are the perceptions and sensory data obtained from situations in which human error prevents us from seeing the..

    Related Articles...

    No related articles found

    See all Related Topics