an orange pigment, C20H28O, that is the active component of rhodopsin and is liberated upon the absorption of light in the vision cycle; vitamin A aldehyde.
Also ret·i·nene [ret-n-een] /ˈrɛt nˌin/.
Origin of retinal2
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
the aldehyde form of the polyene retinol (vitamin A) that associates with the protein opsin to form the visual purple pigment rhodopsin
Word Origin for retinene
C20: from retina + -ene
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Online Etymology Dictionary, © 2010 Douglas Harper
Either of two yellow to red retinal pigments, formed by oxidation of vitamin A alcohols.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.