Final answer:
The trimeric G-protein identified in the light-sensitive cells of the eye is transducin. It is activated by light striking the protein rhodopsin in the photoreceptor cells, leading to the hyperpolarization of the membrane and inhibition of glutamate release.
Step-by-step explanation:
The trimeric G-protein that has been identified in the light-sensitive cells of the eye is transducin. When light strikes the protein called rhodopsin in the photoreceptor cells of the retina, it activates transducin. Transducin then triggers a series of downstream events that lead to the hyperpolarization of the membrane and the inhibition of glutamate release to the bipolar cells.