opsin

noun

op·​sin ˈäp-sən 

: any of various colorless proteins that in combination with retinal or a related prosthetic group form a visual pigment (such as rhodopsin) in a reaction reversible by light

Examples of opsin in a Sentence

Recent Examples on the Web

By tracking changes in skin color, the light-sensitive opsins could allow hogfish to fine-tune their color changing to match their surroundings. —Will Sullivan, Smithsonian Magazine, 24 Aug. 2023

The opsins actually reside in other cells that are located directly beneath them. —Laura Baisas, Popular Science, 23 Aug. 2023

Rod cells, by contrast, use rod opsin and are responsible for night vision. —Roni Dengler, Discover Magazine, 10 May 2019

Word History

Etymology

from -opsin (in porphyropsin and rhodopsin)

Note: Term introduced by the American physiologist George Wald (1906-97) in "The Chemistry of Rod Vision," Science, vol. 113, issue 2933, March 16, 1951, p. 287: "Rhodopsin and porphyropsin are carotenoid-proteins—proteins bearing carotenoid prosthetic groups to which they owe their color and sensitivity to light. Each of these pigments possesses a single type of prosthetic group. The protein probably varies from one animal to another; it may be called opsin, and named for the animal of origin."

First Known Use

1951, in the meaning defined above

Rhymes for opsin

• bacteriorhodopsin
• rhodopsin

Medical Definition

opsin

noun

op·​sin ˈäp-sən 

: any of various colorless proteins that in combination with retinal or a related prosthetic group form a visual pigment (as rhodopsin) in a reaction which is reversed by light