| 释义 |
carotene
caroteneorange fat-soluble pigments found in some plants, such as carrots; vitamin A
Not to be confused with:keratin – a substance found in the dead outer skin and in horn, hoofs, nails, claws, etc.car·o·tene C0121400 (kăr′ə-tēn′) also car·o·tin (-tĭn)n. An orange-yellow to red crystalline pigment, C40H56, found in animal tissue and certain plants, such as carrots and squash. It exists in several isomeric forms and is converted to vitamin A in the liver.
[German Karotin, from Latin carōta, carrot; see carrot.]carotene (ˈkærəˌtiːn) or carotinn (Biochemistry) any of four orange-red isomers of an unsaturated hydrocarbon present in many plants (β-carotene is the orange pigment of carrots) and converted to vitamin A in the liver. Formula: C40H56[C19 carotin, from Latin carōta carrot; see -ene]car•o•tene (ˈkær əˌtin) also car•o•tin (-tɪn)
n. any of three yellow or orange fat-soluble pigments having the formula C40H56, found in many plants, esp. carrots, and transformed into vitamin A in the liver; provitamin A. [1860–65; < Late Latin carōt(a) carrot + -ene] car·o·tene (kăr′ə-tēn′) An organic compound that occurs as an orange-yellow to red pigment in many plants and in animal tissue. In animals, it is converted to vitamin A by the liver. Carotenes give plants such as carrots, pumpkins, and dandelions their characteristic color.Thesaurus| Noun | 1. | carotene - an orange isomer of an unsaturated hydrocarbon found in many plants; is converted into vitamin A in the livercarotin, provitamin Abeta-carotene - an isomer of carotene that is found in dark green and dark yellow fruits and vegetablesprovitamin - vitamin precursor; a substance that is converted into a vitamin in animal tissues | | 2. | carotene - yellow or orange-red fat-soluble pigments in plantscarotenoid - any of a class of highly unsaturated yellow to red pigments occurring in plants and animals |
Translationscarotene
carotene (kâr`ətēn'), long-chained, unsaturated hydrocarbon found as a pigment in many higher plants, particularly carrots, sweet potatoes, and leafy vegetables. Carotene is thought to assist in trapping light energy for photosynthesisphotosynthesis
, process in which green plants, algae, and cyanobacteria utilize the energy of sunlight to manufacture carbohydrates from carbon dioxide and water in the presence of chlorophyll. Some of the plants that lack chlorophyll, e.g.
..... Click the link for more information. or to aid in chemical reduction. It is important in animal biology as the main dietary source of vitamin A (see vitaminvitamin,
group of organic substances that are required in the diet of humans and animals for normal growth, maintenance of life, and normal reproduction. Vitamins act as catalysts; very often either the vitamins themselves are coenzymes, or they form integral parts of coenzymes.
..... Click the link for more information. ), which is produced by splitting one molecule of carotene into two molecules of vitamin A. Carotene that is thus converted is called provitamin A. This reaction occurs in either the liver or intestinal wall. The absorption of dietary carotene is dependent on the action of bile. Its absorption is less efficient than that of vitamin A. High intake of dietary carotene is being studied for its disease prevention potential. Carotenes are the simplest of a group of natural pigments called carotenoids, of which there are more than 600.carotene[′kar·ə‚tēn] (biochemistry) C40H56 Any of several red, crystalline, carotenoid hydrocarbon pigments occurring widely in nature, convertible in the animal body to vitamin A, and characterized by preferential solubility in petroleum ether. Also known as carotin. carotene, carotin any of four orange-red isomers of an unsaturated hydrocarbon present in many plants (β-carotene is the orange pigment of carrots) and converted to vitamin A in the liver. Formula: C40H56 carotene
carotene [kar´o-tēn] a yellow or red pigment found in many dark green, leafy, and yellow vegetables such as collards, turnips, carrots, sweet potatoes, and squash, as well as in yellow fruit, milk, egg yolk, and body fat; it is a chromolipoid hydrocarbon existing in four forms (α-, β-, γ-, and δ-carotene), which can be converted into vitamin A in the body.beta carotene 1. the β isomer of carotene.2. a preparation of this substance administered orally to prevent vitamin A deficiency and to reduce photosensitivity in patients with protoporphyria" >erythropoietic protoporphyria. Written also betacarotene and β-carotene.car·o·tene (kar'ō-tēn), A member of a class of carotenoids, yellow-red pigments (lipochromes) widely distributed in plants and animals, notably in carrots, and closely related in structure to the xanthophylls and lycopenes and to the open-chain squalene; of particular interest in that they include precursors of the vitamins A (provitamin A carotenoids). Chemically, they consist of 8 isoprene units in a symmetric chain with the 2 isoprenes at each end cyclized, forming either α-carotene or β-carotene (γ-carotene has only one end cyclized). The cyclic ends of β-carotene are identical β-ioninelike structures; thus, on oxidative fission, β-carotene yields 2 molecules of vitamin A. The cyclic ends of α-carotene differ in that one is an α-ionone and the other a β-ionone; on fission, α-carotene, like γ-carotene, yields 1 molecule of vitamin A (a β-ionone derivative).carotene (kăr′ə-tēn′) also carotin (-tĭn)n. An orange-yellow to red crystalline pigment, C40H56, found in animal tissue and certain plants, such as carrots and squash. It exists in several isomeric forms and is converted to vitamin A in the liver.car·o·tene (kar'ō-tēn) Yellow-red pigments (lipochromes) widely distributed in plants and animals, notably in carrots, and closely related in structure to the xanthophylls and lycopenes and to the open-chain squalene; they include precursors of vitamin A (provitamin A carotenoids). carotene One of a group of orange pigments found in carrots and some other vegetables. Beta-carotene (provitamin A) is converted to vitamin A in the liver. This vitamin is needed for normal growth and development of bone and skin, for the development of the fetus and for the proper functioning of the RETINA.carotene an orange plant pigment of the CAROTENOID group which is usually present in the CHLOROPLASTS, and sometimes occurs in pigment-containing structures called CHROMOPLASTS which are found in yellow/orange leaves, vegetables and fruits. Carotene is also found in green leaves but the colour is masked; the orange colour can be seen in autumn leaves as the chlorophylls break down first. Carotene is necessary for the production of vitamin A in man and has an ABSORPTION SPECTRUM of about 450 nm. Carotene acts as an accessory pigment, passing energy to chlorophyll a for use in LIGHT REACTIONS and protecting chlorophyll from excessive light, and from oxidation by the oxygen produced in PHOTOSYNTHESIS.car·o·tene (kar'ō-tēn) Yellow-red pigments widely distributed in plants and animals, notably in carrots; include precursors of vitamin A. carotene
Related to carotene: alpha caroteneSynonyms for carotenenoun an orange isomer of an unsaturated hydrocarbon found in many plantsSynonymsRelated Wordsnoun yellow or orange-red fat-soluble pigments in plantsRelated Words |