Answer:
A. Archaea / Bacteria
Explanation:
Bacteriorhodopsin is a protein used by Archaea, most notably by halobacteria, a class of the Euryarchaeota. It acts as a proton pump; that is, it captures light energy and uses it to move protons across the membrane out of the cell
Bacteriorhodopsin is an integral membrane protein usually found in two-dimensional crystalline patches known as "purple membrane", which can occupy up to nearly 50% of the surface area of the archaeal cell.
Proteorhodopsin also known as pRhodopsinbis a family of over 50 photoactive retinylidene proteins, a larger family of transmembrane proteins that use retinal as a chromophore for light-mediated functionality, in this case, a proton pump
A it refers to the speed of the conversion to substrate
Electrons get “excited” or charged by sunlight, then they move on through the photosystem 2 and 1 along the etc or electron transport chain