Final answer:
Bacteriorhodopsin uses sunlight to pump protons out of the cell, creating an electrochemical gradient that enables ATP synthesis.
Step-by-step explanation:
The transmembrane protein bacteriorhodopsin uses sunlight as the source of energy to pump protons out of the cell. When light strikes bacteriorhodopsin, it undergoes a conformational change, causing protons to accumulate on one side of the membrane. The flow of protons down the electrochemical gradient allows ATP to be synthesized.
Bacteriorhodopsin is a transmembrane protein that uses sunlight to pump protons out of the cell, creating an electrochemical gradient used to produce ATP. In contrast, the related protein rhodopsin in vertebrates works in vision by triggering a signal transduction pathway that affects nerve impulses.
The transmembrane protein bacteriorhodopsin uses sunlight as the source of energy to pump protons out of the cell. This process is crucial for creating an electrochemical gradient across the membrane. Bacteriorhodopsin functions by absorbing light to acquire protons from the cytosol, undergoing a conformational change, and then releasing protons on the outside of the membrane. The built-up proton gradient allows protons to flow back into the cell down their electrochemical gradient, which is associated with the synthesis of ATP, an essential molecule for energy storage and transfer within cells.
Comparatively, in vertebrates, when light strikes rhodopsin, a related pigment in the eyes, it triggers a change from a cis to a trans form in the molecule retinal, which is part of the protein. This conformational change activates a G-protein called transducin, leading to downstream events that ultimately result in the hyperpolarization of the membrane, affecting vision and nerve impulses.
Therefore, in Halobacterium, an organism that contains bacteriorhodopsin, the energy from sunlight is directly harnessed to establish a concentration gradient of protons across the membrane, contributing to energy production in the cell.