MCQs on Iron, Folic Acid and Vitamin B12 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) Red blood cell hemoglobin
2) The primary function of transferrin (glycoprotein) in the blood is to bind to and transport iron from areas of the body where it is absorbed to sites where it is needed.
Which of 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 (stored) 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 a medical condition marked by reduced hemoglobin levels and a distinct insufficiency of iron. Iron deficiency is typified 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
B) Folic Acid and Vitamin B-12 (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 which of the following trace element?
a) Iron
b) Copper
c) Cobalt
d) Selenium
14) The intestinal absorption of cobalamin requires which of 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 vitamin B-12 (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 biologically active form of Vitamin B-12 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. Ferritin is primarily responsible for storing iron within cells. It stores iron in a non-toxic and insoluble form, preventing the harmful buildup of free iron ions in the cell.
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. Methylcobalamin is a form of vitamin B12, which is an essential nutrient for the body. It is one of the active and naturally occurring forms of vitamin B12 and is used in various biological processes such as nerve function, red blood cell production, and DNA synthesis and repair.
best
ReplyDelete