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Pronunciation: ro-dop'sin

Definition: 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 purple

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© Copyright 2018 Wolters Kluwer. All Rights Reserved. Review date: Sep 19, 2016.