from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The pigment sensitive to red light in the retinal rods of the eyes, consisting of opsin and retinene. Also called visual purple.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A light-sensitive pigment in the rod cells of the retina; it consists of an opsin protein bound to the carotenoid retinal
from the GNU version of the Collaborative International Dictionary of English
- n. The visual purple. See under visual.
from The Century Dictionary and Cyclopedia
- n. Visual purple; a pigment found in the outer segments of the retinal rods.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a red photopigment in the retinal rods of vertebrates; dissociates into retinene by light
Another protein is rhodopsin, which is found in cells that make up the retina of the eye.
The scientists were able to see previously unobserved changes in the structure of rhodopsin, which is a model for the ubiquitous G protein coupled receptors (GPCRs), heptahelical, transmembrane receptors found in eukaryotic cells.
Saranak J, Patel N, Zarilli G, Okabe M, et al. (1984) A rhodopsin is the functional photoreceptor for phototaxis in the unicellular eukaryote
Blurred vision can be a lack of a light sensitive pigment called rhodopsin, or visual purple, that’s composed of vitamin A and protein.
This alters the way in which one of the proteins in the retina—rhodopsin, a pigment responsible for night vision as well as blue-green color vision—behaves.
Deyes goes on to discuss rhodopsin before throwing this red hot pepper in the pot:
De Santis says their retinal rhodopsin was destroyed.
They have opsins that they use for both light detection (sensory rhodopsin-I and sensory rhodopsin-II) *and* photosynthesis without chlorophyll (bacteriorhodopsin and halorhodopsin).
Surprisingly, it looks as if the critical light-sensitive protein at the centre of it all, rhodopsin, evolved from an ancestor in algae where it is used to calibrate light levels in photosynthesis.
Some bacteria even use rhodopsin for a type of photosynthesis.