The conformational change of retinal, from the cis to the trans configuration, indirectly: A)depolarizes the photoreceptor by closing Na⁺channels. B)depolarizes the photoreceptor by opening Na⁺channels. C)hyperpolarizes the photoreceptor by closing Na⁺channels. D)repolarizes the photoreceptor by closing Na⁺channels.

Question

Quizplus · Accepted Answer

The conformational change of retinal, from the cis to the trans configuration, indirectly hyperpolarizes the photoreceptor by closing Na⁺channels. This closure of channels reduces the influx of positive ions, which decreases the depolarization of the cell and results in hyperpolarization. This is due to the fact that photoreceptors use a unique signaling mechanism in which light-induced hyperpolarization occurs instead of depolarization.

The Conformational Change of Retinal, from the Cis to the Trans