Which of the following statements accurately describes vitamin A's role in vision?

Question

Quizplus · Accepted Answer

Vitamin A participates in the synthesis of rhodopsin, a pigment molecule in the retina that is responsible for vision in low light conditions. Rhodopsin consists of the protein opsin and a molecule of 11-cis-retinal (a form of vitamin A). When light enters the eye, it causes 11-cis-retinal to shift to a trans configuration, which initiates a signal that eventually leads to vision. Retinoic acid (choice A) is a different form of vitamin A that plays a role in gene expression and cell differentiation, but not in vision. Retinol (choice C) is a storage form of vitamin A, but it is not bound to beta-carotene in the corneal membrane. Pigment molecules in the retina contain vitamin A and a different protein, called opsin (not elastin as in choice D). Retinol does not protect the visual cortex (part of the brain involved in processing visual information) from teratogenic (causing birth defects) chemicals (choice E).

Which of the Following Statements Accurately Describes Vitamin A's Role