Final answer:
The two components of rhodopsin are the protein opsin and the cofactor retinal. They play a crucial role in converting light into electrical signals in the retina for vision in low-light conditions. The process involves photoisomerization where retinal changes shape when illuminated.
Step-by-step explanation:
The two moieties of rhodopsin are opsin and retinal. Rhodopsin is the photopigment molecule found in the rod cells of the retina, which are responsible for vision in low-light conditions. Opsin is a transmembrane protein that binds to the cofactor retinal. When light strikes retinal, it undergoes a structural change from a cis to a trans form, a process referred to as photoisomerization. This change triggers a cascade of biochemical events that ultimately convert light into an electrical signal, which is processed by the brain as vision.
Photoreceptor cells in the eye, including rods and cones, rely on pigments like rhodopsin for phototransduction. Rods are extremely sensitive to light, allowing them to function in dimly lit environments. The retinal within the opsin protein is vital for this light sensitivity, with specific wavelengths of light triggering different responses. Rhodopsin is most sensitive to 498 nm light.