cis-retinal

cis-retinal

(sĭs′rĕt′ĭ-năl, rĕt″năl) [L. prefix cis-, this side of + ″]
The form of retinal combined with a glycoprotein opsin (rhodopsin in rods) during darkness. Light striking the retina changes it to trans-retinal and begins the generation of a nerve impulse.
Mentioned in ?