The ability of the eye to see in the dark is due to the production of a purple pigment known as (a) Carotene (b) Rhodopsin (c) Iodopsin (d) Retinene
Option D) Retinene–1 is better known as retinaldehyde or simply retinal and is fundamental in the transduction of light into visual signals in the photoreceptor level of the retina (known as the visual cycle). Retinene–2 is more formally known as dehydroretinaldehyde. The energy of impinging photons will convert retinaldehyde from an 11-cis isomer into an all-trans form. In the retina, this conversion induces a conformational change in the surrounding photopsin protein pigment, leading to signaling through the G protein transducin. Retinaldehyde also forms a part of bacteriorhodopsin, a light-induced proton pump found in some archaea.
