Iron, Folic Acid and Vitamin B12 Metabolism (MCQs)

Iron Metabolism

1) The majority of iron in the body is present in
a) Iron bound to transferrin
b) Iron stored in the liver
c) Myoglobin
d) Hemoglobin

2) Transferrin is the proteins that bind to iron in circulation and delivered to the target tissues (erythroid, liver) via transferrin. Which if the following statement is true regarding transferrin receptor
a) The clearance of iron-bound transferrin is affected by circulatory iron
b) Transferrin can occur in monoferric or diferric form
c) The transferring binds to the transferrin receptor and endocytosed to release iron
d) All of the above

3) The intracellular iron is rapidly sequestered by 
a) Transferrin
b) Ferrochelatase 
c) Ferritin
d) Albumin

4) Approximately 1 mg of iron needs to be replenished daily from the dietary source. The absorption of dietary iron is facilitated by divalent metalloprotein transported 1 (DMT 1). Iron is absorbed in 
a) Ferrous form
b) Ferric form
c) Heme Iron form
d) None of the above

5) Iron deficiency Anemia is the condition in which there is decreased hemoglobin and a clear deficiency of iron. Iron deficiency is characterized by
a) Increased total iron binding capacity > 360 ug/dL
b) Decreased ferritin < 15 ug/L
c) Decreased Serum Iron < 50 ug/dL
d) All  of the above

Folic Acid and Cobalamin Metabolism
6) Folic acid is present in the tetrahydrofolic acid and dihydro-folic acid. Which of these are biologically active forms?
a) Tetrahydrofolic acid
b) Dihydrofolic acid
c) Both
d) None

7) In the intestinal cells, first the folate is reduced and ..................... before it enters into the circulation. In the circulation, it binds loosely to albumin
a) Acetylation
b) Methylation
c) Formylation
d) Adenosylation

8) In adults, the daily dietary requirement of folic acid in the body is 
a) 4000 micrograms
b) 400 micrograms
c) 40 micrograms
d) 4 micrograms

9) Which of the following form of folic acid is an active methyl group donor?
a) 5-Methyl tetrahydrofolate
b) N5-N10 methylene tetrahydrofolate
c) Formly tetrahydrofolate
d) None of the above

10) Folate trap occurs when the methyl-tetrahydrofolate is accumulated and not recycled into tetrahydrofolate. Which of the vitamin deficiency lead to folate trap
a) Pyridoxine
b) Niacin
c) Cobalamin
d) Riboflavin

11) Which of the following metabolic intermediate of amino acids are accumulated in subjects with folic acid deficiency
a) S-Adenosylhomocysteine
b) Foriminoglutamic acid
c) para-amino benzoic acid
d) Glutathione

12) Which of the following is the characteristic feature of anemia caused by the folic acid deficiency
a) Microcytic anemia
b) Megaloblastic anemia
c) Hypochromic anemia 
d) None of the above

13) In Cobalamin (Vit B12), the corrin ring is bound to this trace element
a) Iron
b) Copper
c) Cobalt
d) Selenium

14) The intestinal absorption of cobalamin requires the following proteins
a) Intrinsic Factor
b) Transcobalamin
c) TcII receptor
d) All of the above

15) Which of the following is the specific transport protein for cobalamin
a) Intrinsic Factor
b) Transcobalamin
c) TcII receptor
d) All of the above

16) Pernicious anemia is an autoimmune disorder that results in the deficiency of cobalamin. In pernicious anemia, the auto-antibodies are generated against
a) Intrinsic Factor
b) Transcobalamin
c) TcII receptor
d) All of the above

17) The defect in the enzyme that catalyzes the synthesis of S-adenosylcobalamin results in 
a) Homocysteinuria
b) Alkaptonuria 
c) Methylmalonic aciduria
d) Phenylketonuria

18) Which of the following organ serves as storage for cobalamin
a) Liver
b) Kidney
c) Spleen 
d) Bone marrow

19) The adult dietary requirement of cobalamin is 
a) 0.24 microgram/day
b) 2.4 microgram/day
c) 24 microgram/day
4) 240 micogram/day

20) Which of the following physiological form is predominantly present in serum
a) Adenosylcobalamin
b) Methylcobalamin
c) Cyanocobalamin
d) Hydoxylcobalamin

MCQ Answers 
1-d) Hemoglobin
2-d) All of the above
3-c) Ferritin
4-a) Ferrous form
5-d) All  of the above
6-a) Tetrahydrofolic acid
7-b) Methylation
8- b) 400 micrograms
9-a) 5-Methyl tetrahydrofolate
10-d) Cobalamin
11-b) Foriminoglutamic acid
12-b) Megaloblastic anemia
13)-c) Cobalt
14-d) All of the above
15-b) Transcobalamin
16-a) Intrinsic Factor
17-c) Methylmalonic aciduria
18-a) Liver
19-b) 2.4 microgram/day
20-b) Methylcobalamin

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