Some Strains of Haloarchaea Exhibit

Question

Some strains of haloarchaea exhibit
A) anoxic growth at the expense of sugar fermentation.
B) anaerobic respiration.
C) anoxygenic photosynthesis.
D) light-driven ATP synthesis under oxygen-limiting conditions.

Accepted Answer

Some strains of haloarchaea can use light energy to drive ATP synthesis, known as photophosphorylation, under oxygen-limiting conditions in their habitats. This is achieved through a type of retinal-based, proton-pumping rhodopsin called bacteriorhodopsin, which is found in the plasma membrane of these organisms. Bacteriorhodopsin absorbs light to transport protons out of the cell, generating an electrochemical gradient that can be used to synthesize ATP via ATP synthase. This is a form of anoxygenic photosynthesis that doesn't generate oxygen as a byproduct and doesn't require the presence of chlorophyll pigments.