Which of the Following Uses Light to Generate a Proton

Question

Which of the following uses light to generate a proton gradient in the haloarchaeotes?
A) bacteriorhodopsin
B) bacterioruberin
C) halorhodopsin
D) methanofuran
E) ferredoxin

Accepted Answer

Bacteriorhodopsin is a light-driven proton pump that uses light to generate a proton gradient in the haloarchaeotes. It is a type of rhodopsin that is found in the plasma membrane of halophilic archaea, such as Halobacterium salinarum. It absorbs light in the green portion of the spectrum and uses the energy to transport protons out of the cell, creating a proton gradient that can be used for ATP synthesis. Bacteriorhodopsin is also used in optogenetics, a method for controlling cells with light.