Which substance is formed when rhodopsin is activated?

When rhodopsin, a light-sensitive pigment found in the photoreceptors of the retina, is activated by light, it undergoes a conformational change and ultimately leads to the formation of metarhodopsin II. This process involves several steps: the light photon causes a change in the structure of the rhodopsin molecule, converting it from a stable form to the active form known as metarhodopsin II.

Metarhodopsin II plays a crucial role in the phototransduction cascade, a signaling pathway that converts light signals into electrical signals within the retina. This active form of rhodopsin promotes the activation of transducin, a G-protein that initiates a series of biochemical events resulting in hyperpolarization of the photoreceptor cell and ultimately the perception of light.

The significance of metarhodopsin II in this process cannot be overstated, as it is the key intermediate that triggers the phototransduction cascade, facilitating vision under low-light conditions. Other potential products of rhodopsin activation may not directly participate in the initial step of the signal transduction pathway. Thus, metarhodopsin II is identified as the primary substance formed following the activation of rhodopsin