Menu

Rhodopsin

9. Februar 2017 - Eye, Ophthalmology

The rhodopsin is a transmembrane protein that, in humans, is in the records of the rods of the retina . It consists of a protein part, opsin , and a non – protein which is a derivative of vitamin A which is the 11-cis-retinal . It is unstable and easily alters with light energy, discolours and decomposes by exposure to light and regenerates with darkness.

A majority marine microorganisms photosynthetic capture energy from sunlight by rhodopsin. Protein allows these organisms to use the energy of the sun to move, grow and survive in the absence of nutrients. Rhodopsin is highly conserved and present in the three domains ( archaea , bacteria and eukaryotes ), suggesting an early onset and a key role in evolution. 1

Opsin is a polypeptide chain made up of about 348 amino acids. Opsin is distributed into seven sections of alpha helix which lie perpendicular to the membrane bound protein parts by structureless.

It is also called visual purple, because of their color since he first found in the retina of frogs Franz Boll .

The terminal carboxyl is located in the cytosolic part and the amino in the intradiscal position.

The 11-cis-retinal is attached to one of the alpha helices in the center of the molecule and placed perpendicularly. This placement causes that when light reaches the 11-cis-retinal and it is transformed producing reactions that lead to a nerve impulse.

Function

Rods containing rhodopsin are responsible for vision in low light conditions.

References

  1. Back to top↑ A protein allows half of the non – photosynthetic microorganisms sea obtain energy from light . Agrifying. November 4, 2016.