Vitamin-A

Question 1

Inactive form of vitamin A?

Answer 1

Beta carotene.

Question 2

Compounds having vitamin A activity are called?

Answer 2

Retinoids.

Question 3

Whose trans variety makes vitamin A1?

Answer 3

Retinal.

Question 4

How can vitamin A1 can be converted to vitamin A2?

Answer 4

By adding extra double bond in vitamin A1.

Question 5

Major absorption site of vitamin A?

Answer 5

Intestine.

Question 6

Which form of Vitamin A is absorbed?

Answer 6

Retinal.

Question 7

Without which substances vitamin A can’t be absorbed?

Answer 7

Fats and bile salts.

Question 8

In which form vitamin is stored in liver?

Answer 8

Retinal palmitate.

Question 9

With which substance trans retinal is transported from liver to peripheral tissues?

Answer 9

Retinal binding protein (RBP).

Question 10

Membrane protein found in photoreceptor cells of retina ?

Answer 10

Rhodopsin.

Question 11

Which photosensitive cell is for Dim light?

Answer 11

Rods.

Question 12

What is rhodopsin of rod made up of?

Answer 12

11-cis retinal + opsin.

Question 13

How many rods are there per eye?

Answer 13

120 million.

Question 14

Deficiency of 11-cis retinal will cause?

Answer 14

Dark adaptation time increases.

Night blindness.

Question 15

Which protein is found in cones?

Answer 15

Conopsin .

Question 16

Which photosensitive cell is responsible for bright light?

Answer 16

Cones.

Question 17

Deficiency of cones cause?

Answer 17

Colour blindness.

Question 18

No. of cones per eye?

Answer 18

6 million.

Question 19

Which synthetic variant of vitamin A prevents acne ?

Answer 19

Isoretinone.

Question 20

In which case, conjunctiva becomes dry and get keratinised and leads to keratinisation of cornea?

Answer 20

Xerophthalmia.

Question 21

In which case, grey- whitish plaques are seen adherent to conjunctiva?

Answer 21

Bitot spots.

Question 22

If xerophthalmia persists for long term, leads to softening of cornea , what is the diagnosis?

Answer 22

Keratomalacia.