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VITAMINS- Part 1
See all quizzes of VITAMINS- Part 1 here:
1. Vitamins are
(A) Accessory food factors
(B) Generally synthesized in the body
(C) Produced in endocrine glands
(D) Proteins in nature
2. Vitamin A or retinal is a
(A) Steroid
(B) Polyisoprenoid compound containing a
cyclohexenyl ring
(C) Benzoquinone derivative
(D) 6-Hydroxychromane
3. β-Carotene, precursor of vitamin A, is
oxidatively cleaved by
(A) β-Carotene dioxygenase
(B) Oxygenase
(C) Hydroxylase
(D) Transferase
4. Retinal is reduced to retinol in intestinal
mucosa by a specific retinaldehyde
reductase utilising
(A) NADPH + H+ (B) FAD
(C) NAD (D) NADH + H+
5. Preformed Vitamin A is supplied by
(A) Milk, fat and liver
(B) All yellow vegetables
(C) All yellow fruits
(D) Leafy green vegetables
CHAPTER 5
VITAMINS
6. Retinol and retinal are interconverted
requiring dehydrogenase or reductase in
the presence of
(A) NAD or NADP (B) NADH + H+
(C) NADPH (D) FAD
7. Fat soluble vitamins are
(A) Soluble in alcohol
(B) one or more Propene units
(C) Stored in liver
(D) All these
8. The international unit of vitamin A is
equivalent to the activity caused by
(A) 0.3 μg of Vitamin A alcohol
(B) 0.344 μg of Vitamin A alcohol
(C) 0.6 μg of Vitamin A alcohol
(D) 1.0 μg of Vitamin A alcohol
9. Lumirhodopsin is stable only at temperature
below
(A) –10°C (B) –20°C
(C) –40°C (D) –50°C
10. Retinol is transported in blood bound to
(A) Aporetinol binding protein
(B) α2-Globulin
(C) β-Globulin
(D) Albumin
112 MCQs IN BIOCHEMISTRY
11. The normal serum concentration of
vitamin A in mg/100 ml is
(A) 5–10 (B) 15–60
(C) 100–150 (D) 0–5
12. One manifestation of vitamin A deficiency
is
(A) Painful joints
(B) Night blindness
(C) Loss of hair
(D) Thickening of long bones
13. Deficiency of Vitamin A causes
(A) Xeropthalmia
(B) Hypoprothrombinemia
(C) Megaloblastic anemia
(D) Pernicious anemia
14. An important function of vitamin A is
(A) To act as coenzyme for a few enzymes
(B) To play an integral role in protein synthesis
(C) To prevent hemorrhages
(D) To maintain the integrity of epithelial tissue
15. Retinal is a component of
(A) Iodopsin (B) Rhodopsin
(C) Cardiolipin (D) Glycoproteins
16. Retinoic acid participates in the synthesis
of
(A) Iodopsin (B) Rhodopsin
(C) Glycoprotein (D) Cardiolipin
17. On exposure to light rhodopsin forms
(A) All trans-retinal (B) Cis-retinal
(C) Retinol (D) Retinoic acid
18. Carr-Price reaction is used to detect
(A) Vitamin A (B) Vitamin D
(C) Ascorbic acid (D) Vitamin E
19. The structure shown below is of
(A) Cholecalciferol
(B) 25-Hydroxycholecalciferol
(C) Ergocalciferol
(D) 7-Dehydrocholesterol
20. Vitamin D absorption is increased in
(A) Acid pH of intestine
(B) Alkaline pH of intestine
(C) Impaired fat absorption
(D) Contents of diet
21. The most potent Vitamin D metabolite is
(A) 25-Hydroxycholecalciferol
(B) 1,25-Dihydroxycholecalciferol
(C) 24, 25-Dihydroxycholecalciferol
(D) 7-Dehydrocholesterol
22. The normal serum concentration of
25-hydroxycholecalciferol in ng/ml is
(A) 0–8 (B) 60–100
(C) 100–150 (D) 8–55
23. The normal serum concentration of 1,25-
dihydroxycholecalciferol in pg/ml is
(A) 26–65 (B) 1–5
(C) 5–20 (D) 80–100
24. The normal serum concentration of 24,25-
dihydroxycholecalciferol in ng/ml is
(A) 8–20 (B) 25–50
(C) 1–5 (D) 60–100
25. A poor source of Vitamin D is
(A) Egg (B) Butter
(C) Milk (D) Liver
26. Richest source of Vitamin D is
(A) Fish liver oils (B) Margarine
(C) Egg yolk (D) Butter
27. Deficiency of vitamin D causes
(A) Ricket and osteomalacia
(B) Tuberculosis of bone
(C) Hypthyroidism
(D) Skin cancer
28. One international unit (I.U) of vitamin D
is defined as the biological activity of
(A) 0.025 μg of cholecalciferol
(B) 0.025 μg of 7-dehydrocholecalciferol
(C) 0.025 μg of ergosterol
(D) 0.025 μg of ergocalciferol
VITAMINS 113
29. The β-ring of 7-dehydrocholesterol is
cleaved to form cholecalciferol by
(A) Infrared light
(B) Dim light
(C) Ultraviolet irridation with sunlight
(D) Light of the tube lights
30. Calcitriol synthesis involves
(A) Both liver and kidney
(B) Intestine
(C) Adipose tissue
(D) Muscle
