Share this entry

opsin Line breaks: opsin
Pronunciation: /ˈɒpsɪn/

Definition of opsin in English:


[mass noun] Biochemistry
A protein which forms part of the visual pigment rhodopsin and is released by the action of light.
Example sentences
  • Rhodopsin consists of a protein called opsin bonded to a pigment called retinal.
  • Vitamin A then combines with a protein opsin to form rhodopsin.
  • Visual pigments are composed of a light-absorbing chromophore that is bound to the protein opsin.


1950s: shortening of rhodopsin.

Definition of opsin in:

Share this entry


What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.

Get more from Oxford Dictionaries

Subscribe to remove adverts and access premium resources

Word of the day innocuous
Pronunciation: ɪˈnɒkjʊəs
not harmful or offensive