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[roh-dop-sin] /roʊˈdɒp sɪn/
noun, Biochemistry
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.
Also called visual purple.
Origin of rhodopsin
1885-90; rhod- + Greek óps(is) sight, vision + -in2 Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the web for rhodopsin
  • He has also found numerous genes for versions of rhodopsin.
  • The visual purple or rhodopsin is found only in the outer segments.
  • The action of a photon on a rhodopsin molecule in a retinal cell has some quantum mechanical interpretations, and so forth.
British Dictionary definitions for rhodopsin


a red pigment in the rods of the retina in vertebrates. It is dissociated by light into retinene, the light energy being converted into nerve signals, and is re-formed in the dark Also called visual purple See also iodopsin
Word Origin
C20: from rhodo- + -opsis + -in
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
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rhodopsin in Medicine

rhodopsin rho·dop·sin (rō-dŏp'sĭn)
A thermolabile protein that is sensitive to red light and is found in the external segments of the rods of the retina of the eye. Also called visual purple.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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