| 释义 |
opsin
op·sin O0099600 (ŏp′sĭn)n. Any of various light-sensitive proteins, especially one that is a constituent of a rhodopsin or other visual pigment found in the retina of the vertebrate eye.
[Probably back-formation from rhodopsin.]opsin (ˈɒpsɪn) n (Biochemistry) the protein that together with retinene makes up the purple visual pigment rhodopsin[C20: back formation from rhodopsin]op•sin (ˈɒp sɪn)
n. any of several compounds that form the protein component of the light-sensitive pigment rhodopsin. [1950–55; probably back formation from rhodopsin] Thesaurus| Noun | 1. | opsin - retinal protein formed by the action of light on rhodopsinprotein - any of a large group of nitrogenous organic compounds that are essential constituents of living cells; consist of polymers of amino acids; essential in the diet of animals for growth and for repair of tissues; can be obtained from meat and eggs and milk and legumes; "a diet high in protein"iodopsin - a violet photopigment in the retinal cones of the eyes of most vertebrates; plays a role in daylight visionretinal purple, rhodopsin, visual purple - a red photopigment in the retinal rods of vertebrates; dissociates into retinene by light |
EncyclopediaSeeRhodopsinopsin
op·sin (op'sin), The protein portion of the rhodopsin molecule; at least three separate opsins are located in cone cells.opsin (ŏp′sĭn)n. Any of various light-sensitive proteins, especially one that is a constituent of a rhodopsin or other visual pigment found in the retina of the vertebrate eye.op·sin (op'sin) The protein portion of the rhodopsin molecule; at least three separate opsins are located in cone cells. opsin a protein that occurs in rods and cones of the RETINA of the eye, which combines with retinal 1 or retinal2 to form visual pigments.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.opsin
Related to opsin: rhodopsin, opsonin, KIPRISWords related to opsinnoun retinal protein formed by the action of light on rhodopsinRelated Words- protein
- iodopsin
- retinal purple
- rhodopsin
- visual purple
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