Final answer:
Rhodopsin is made of opsin and retinal. Light triggers the retina to change shape, thereby activating rhodopsin which then signals transducing, starting a visual signal cascade.
Step-by-step explanation:
Rhodopsin, the photoreceptor found in vertebrates, is composed of two main components: a protein called opsin and a light-absorbing molecule known as retinal. Upon exposure to light, the retina undergoes a conformational change from cis to trans (referred to as photoisomerization), which activates the rhodopsin and begins a cascade of events in the process of visual transduction. Subsequently, this activation triggers a response in a G-protein named transducing, which plays a crucial role in the downstream signaling events that lead to vision.