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visual purple
visual purplen. See rhodopsin.visual purple n (Biochemistry) another name for rhodopsin rho•dop•sin (roʊˈdɒp sɪn)
n. a bright red photosensitive pigment found in the rod-shaped cells of the retina of certain fishes and most higher vertebrates: it is broken down by the action of dim light into retinal and opsin. [1885–90; rhod- + Greek óps(is) sight, vision + -in1] Thesaurus| Noun | 1. | visual purple - a red photopigment in the retinal rods of vertebrates; dissociates into retinene by lightretinal purple, rhodopsinretinal rod, rod cell, rod - a visual receptor cell that is sensitive to dim lightopsin - retinal protein formed by the action of light on rhodopsinretinal, retinene - either of two yellow to red retinal pigments formed from rhodopsin by the action of lightphotopigment - a special pigment found in the rods and cones of the retina |
visual purple
visual purple: see visionvision,
physiological sense of sight by which the form, color, size, movements, and distance of objects are perceived. Vision in Humans
The human eye functions somewhat like a camera; that is, it receives and focuses light upon a photosensitive receiver, the retina.
..... Click the link for more information. .visual purple[′vizh·ə·wəl ′pər·pəl] (biochemistry) rhodopsin visual purple
purple [pur´p'l] 1. a color between blue and red.2. a substance of this color used as a dye or indicator.visual purple rhodopsin.rho·dop·sin (rō-dop'sin), [MIM*180380] A purplish-red thermolabile protein, MW about 40,000, found in the external segments of the rods of the retina; consists of opsin combined with 11-cis retinal; it is bleached by the action of light, which converts it to opsin and all-trans-retinal, and is restored in the dark by rhodogenesis; the dominant protein in the plasma membrane of rod cells. Synonym(s): visual purplevisual purplen. See rhodopsin.rho·dop·sin (rō-dop'sin) A red thermolabile protein found in the rods of the retina; it is bleached by the action of light, which converts it to opsin and all-trans-retinal, and is restored in the dark by rhodogenesis; the dominant protein in the plasma membrane of rod cells.
Synonym(s): visual purple. visual purple Rhodopsin. A light-sensitive pigment in the rods of the retina that is chemically changed on exposure to light and in the process stimulates production of a nerve impulse. Visual purple is reformed in the dark.rhodopsin Visual pigment contained in the outer segments of the rod cells of the retina and involved in scotopic vision. When light stimulates the retina, the chromophore of the pigment molecule '11-cis' retinal (which is vitamin A aldehyde) isomerizes to 'all-trans' retinal. This leads to other chemical transformations which carry on even in the absence of light. The first stage is prelumirhodopsin, then lumirhodopsin and finally metarhodopsin (of which there are two types). This last transformation may lead to the breakdown of the molecule into retinal and opsin. The molecule is regenerated by recombining retinal and opsin with some enzymes. The absorption spectrum of rhodopsin has a maximum around 498 nm. The isomerization from '11-cis' to 'all-trans' also gives rise to the process of transduction in which the membrane potential covering the pigment molecules in the outer segment changes towards a hyperpolarization of the cell. This is the first step in the nervous response to a light stimulation of the retina. Syn. visual purple (not used any more); erythropsin. See dark adaptation; bleaching; receptor potential; absorption spectrum; transduction.rho·dop·sin (rō-dop'sin) [MIM*180380] A red thermolabile protein found in the rods of the retina.
Synonym(s): visual purple. FinancialSeeVisionvisual purple
Synonyms for visual purplenoun a red photopigment in the retinal rods of vertebratesSynonymsRelated Words- retinal rod
- rod cell
- rod
- opsin
- retinal
- retinene
- photopigment
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