The active form of vitamin A that functions in vision is:
A)opsin.
B)retinol.
C)retinal.
D)retinoic acid.
E)tryptophan.

Question

Quizplus · Accepted Answer

The active form of vitamin A that functions in vision is retinal. Retinal combines with opsin to form rhodopsin, a photopigment in the rods of the retina that detects light and allows for vision in low-light conditions. Retinol is converted to retinal within the retina, but is not the active form involved in vision. Retinoic acid is involved in other biological processes, such as gene expression and cell differentiation, but not in vision. Tryptophan is an amino acid, not a form of vitamin A.

The Active Form of Vitamin a That Functions in Vision