Definition of porphyropsin in US English:

porphyropsin

noun

Biochemistry
  • Any of a class of light-sensitive pigments found in the retinas of freshwater vertebrates, analogous to rhodopsin in humans but differing from it in containing the aldehyde of vitamin A ₂ rather than that of A₁ and in having a maximum absorption of visible light at a slightly longer wavelength.

Origin

1930s. From porphyro- + -opsin. Compare later opsin.

Pronunciation

porphyropsin

/ˌpɔːfɪˈrɒpsɪn/