Definitions

from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. Either of two yellow to red retinal pigments, formed by oxidation of vitamin A alcohols. Also called retinal2.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. Either of two carotenoid pigments found in the retina and produced from vitamin A; retinal

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. either of two yellow to red retinal pigments formed from rhodopsin by the action of light

Etymologies

Sorry, no etymologies found.

Examples

  • Nevertheless in that period, after dissecting retinas from 300 frogs, he found that rhodopsin on stimulation with light yielded both the protein opsin and a compound he called "retinene" (now "retinaldehyde") that in turn yielded vitamin A (now called retinol).

    The Nobel Prize and the Discovery of Vitamins

  • Retinene can exist in two forms, different in molecular shape, called cis-retinene and trans-retinene.

    The Human Brain

  • In the dark, trans-retinene changes into cis-retinene and joins opsin once more to form the rhodopsin.

    The Human Brain

  • If the diet is deficient in vitamin A, the body's stores eventually give out and retinene is not replaced as it is lost.

    The Human Brain

  • Vitamin A, which is more stable, is, however, easily converted into retinene, so that the vitamin A stores of the body can be called upon to replace the constant dribbling loss of this visual pigment.

    The Human Brain

  • In the presence of light, cis-retinene is converted to trans-retinene and, if it already makes up part of the rhodopsin molecule, it falls off, leaving the largely colorless opsin behind.

    The Human Brain

  • The shape of cis-retinene is such that it can combine with opsin to form rhodopsin, whereas trans-retinene cannot.

    The Human Brain

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