Good vision depends on adequate intake of carotene rich food.
Select the best option from the following statements.
(a)Vitamin A derivatives are formed from carotene.
(b)The photopigments are embedded in the membrane discs of the inner segment
(c)Retinal is a derivative of Vitamin A
(d)Retinal is a light absorbing part of all the visual photopigments.
Good vision depends on adequate intake of carotene rich food.
Select the best option from the following statements.
(a)Vitamin A derivatives are formed from carotene.
(b)The photopigments are embedded in the membrane discs of the inner segment
(c)Retinal is a derivative of Vitamin A
(d)Retinal is a light absorbing part of all the visual photopigments.
The correct option is A (a), (c) and (d)
The human retina has four photopigments, one-rod photopigment, and three cone photopigments, all of the similar construction. Each photopigment has two elements: a large protein portion, which is called an opsin, and a small attached molecule called retinal, which is an aldehyde of vitamin A. Retinal is the portion of the photopigment first affected by light absorption and it is considered to be the active part, or chromophore, of the opsin -retinal complex. In the human photopigments, opsin differs from one pigment to another, but the same retinal is used for all. Therefore retinal is essential for good vision. And since retinal is a derivative of vitamin A, which in turn is obtained from carotene, carotene is essential for good vision. Therefore the statements (a), (c) and (d) together explain why good vision depends on adequate intake of carotene rich food, and option 1 is the answer.
The human retina has four photopigments, one-rod photopigment, and three cone photopigments, all of the similar construction. Each photopigment has two elements: a large protein portion, which is called an opsin, and a small attached molecule called retinal, which is an aldehyde of vitamin A. Retinal is the portion of the photopigment first affected by light absorption and it is considered to be the active part, or chromophore, of the opsin -retinal complex. In the human photopigments, opsin differs from one pigment to another, but the same retinal is used for all. Therefore retinal is essential for good vision. And since retinal is a derivative of vitamin A, which in turn is obtained from carotene, carotene is essential for good vision. Therefore the statements (a), (c) and (d) together explain why good vision depends on adequate intake of carotene rich food, and option 1 is the answer.
