Quiz: Bio — AUA MCQ

1.All the following oxygen-handling proteins contain heme as a prosthetic group, except:

A A. Cytochromes B B. Peroxidase C C. Superoxide dismutase D D. Tryptophan pyrrolase

2. The methenyl bridge of protoporphyrin is derived from:

A A. Alpha carbon atom of glycine B B. Alpha carbon atom of succinyl-CoA C C. Carboxyl group of succinyl-CoA D D. Carboxyl group of glycine

3. Rate limiting enzyme in heme synthesis is:

A A. Heme synthase B B. ALA dehydrtase C C. ALA synthase D D. Uroporphyrinogen synthase

4. All the following are precursors of heme, except:

A A. Porphobilinogen B B. Urobilinogen C C. Uroporphyrinogen D D. Protoporphyrinogen

5. Which enzyme of heme biosynthesis is inhibited by lead??

A A. ALA dehydratase B B. UBGI synthase C C. UBG decarboxylase D D. PPG oxidase

6. Acute intermittent porphyria (AIP) is:

A A. Characterized by photodermatitis B B. An autosomal dominant trait C C. More common in men than women D D. Hemolytic anemia is associated

7. Congenital erythropoietic porphyria is caused by deficiency of:

A A. ALA synthase B B. Uroporphyrinogen III cosynthase C C. Coproporphyrinogen oxidase D D. Uroporphyrinogen decarboxylase

8. Urine of a patient with acute intermittent porphyria is likely to contain:

A A. Porphobilinogen B B. Uroporphyrinogen C C. Protoporphyrinogen D D. Bilirubin

:9. Degradation of heme to bilirubin releases one molecule of:

A A. Carbon dioxide B B. Water C C. Ammonia D D. Carbon monoxide

10. Heme is converted to bilirubin in:

A A. Mitochondria B B. Microsomes C C. Golgi bodies D D. Plasma membrane

11. Bilirubin in serum can be measured by:

A A. Van den Bergh reaktion B B. Ehrlich's reaction C C. Schlesinger's reaction D D. Fouchet's reaction

12. Which disease is associated with conjugated hyperbilirubinemia?

A A. Gilbert's disease B B. Crigler-Najjar syndrome C C. Dubin-Johnson's syndrome D D. Congenital spherocytosis

12. Which disease is associated with conjugated hyperbilirubinemia?

A A. Gilbert's disease B B. Crigler-Najjar syndrome C C. Dubin-Johnson's syndrome D D. Congenital spherocytosis

13. All the following have a regulatory effect on heme synthesis, except:

A A. Cellular heme pool B B. Low calorie diet C C. Compartmentalization of enzymes D D. Hematocrit value

15. Which of the following statements is not true?

A A. ALA synthase requires energy for its activity B B. ALA dehydratase is inhibited by lead C C. ALA synthase requires PLP for its activity D D. Two molecules of ALA condense to form PBG

16. Porphyrins are:

A A. Monopyrroles B B. Colorless components C C. Showing fluorescence under UV light D D. Destroyed by sunlight

17. In obstructive jaundice, prothrombin time:

A A. Remains normal B B. Decreases C C. Becomes normal when vitamin K is administered D D. Increases when vitamin K is administered

18. Which does not contain heme?

A A. Myoglobin B B. Cytochrome C C. Ferroxidase D D. Peroxidase

19. All are correct with regard to heme, except:

A A. Ferro protoporphyrin B B. Prosthetic group of cytochromes C C. Synthesized by using glycine D D. Linear tetrapyrrole

20. Which Is required for synthesis of porphyrins?

A A. Ammonia B B. Methionine C C. Glycine D D. Carbon dioxide

21. All are substituent groups present in heme (protoporphyrin), except:

A A. Methyl B B. Vinyl C C. Propionyl D D. Ethyl

22. All are correct regarding heme synthesis, except:

A A. Compartmentalized B B. Stimulated by lead. C C. Regulated by end product inhibition. D D. Induced by barbiturates.

23. All affect heme synthesis, except:

A A. Barbiturates B B. Estrogens C C. Glucose D D. Oncogenes

24. A patient with acute intermittent porphyria should M given:

A A. High carbohydrate diet B B. Barbiturates C C. Aspirin D D. Saline infusion

25. Congenital erythropoietic porphyria has all the features, except:

A A. Sensitivity to sunlight B B. Reddish discoloration of urine C C. Erythrocyte porphyrin level elevated D D. Red fluorescence of teeth

26. Presence of porphyrins in urine can be detected by:

A A. UV fluorescence B B. Absorption band at 565 nm C C. Fouchet's test D D. Schlesinger's test

27. Bilirubin is formed in all the tissues, except:

A A. Liver B B. Spleen C C. Kidney D D. Bone marrow

28. Which is not involved 1·n catabolism of heme?

A A. Cytochrome a B B. NADPH C C. Molecular oxygen D D. Cytochrome c·

29. Which enzyme is not involved in catabolism of heme?

A A. Heme oxygenase B B. UDP-glucuronyltransferase C C. Biliverdin reductase D D. Ferrochelatase

30. All the following are produced from heme during catabolism, except:

A A. Urobilinogen B B. Porphobilinogen C C. Bilirubin D D. Biliverdin

31. Normal color of feces is due to:

A A. Bilirubin B B. Stercobilin C C. Porphobilinogen D D-. Biliverdin

32. All the following compounds undergo enterohepatic circulation, except:

A A. Urobilinogen B B. Iron C C. Cholic acid D D. Cholesterol

33. Increased level of urobilinogen in urine is observed in all the following conditions, except:

A A. Congenital spherocytosis B B. Mismatched transfusion C C. Glucose-6-phosphate dehydrogenase deficiency D D. Lead poisoning

34. Congenital hyperbilirubinemia with a bilirubin level of 2.5 mg/dL is suggestive of:

A A. Crigler-Najjar syndrome B B. Gilbert's syndrome C C. Dubin-Johnson's syndrome D D. Rotor syndrome

35. Heme contains:

A A. Magnesium B B. Calcium C C. Iron D D. Sodium

36. Heme is not found in:

A A. Cytochrome c B B. Cytochrome a C C. Iron sulfur proteins D D. Nitric oxide synthase

37. Bilirubin is:

A A. Conjugated with glucuronic acid B B. Transported free in plasma C C. Normally excreted through urine D D. Bound to haptoglobin

38. UPG is converted to CPG by:

A A. Condensation B B. Decarboxylation C C. Dehydrogenation D D. Reduction

39. Which of the following is colored'?

A A. PBG B B. UPG C C. CPG D D. PP

40. Heme synthesis requires all the following, except:

A A. Glycine B B. Succinyl-CoA C C. PLP D D. Cytochrome P-450

40. Heme synthesis requires all the following, except:

A A. Glycine B B. Succinyl-CoA C C. PLP D D. Cytochrome P-450

4I. All are Features of acute intermittent porphyria, except:

A A. Abdominal colic B B. Hypertension C C. Anemia D D. Psychotic behavior

42. Which porphyria is inherited as an autosomal recessive trait?

A A. Hereditary coproporphyria B R. Porphyria cutanea tarda C C. Acute intermittent porphyria D D. Congenital erythropoietic porphyria

43. Which of the following is not true regarding bilirubin?

A A. It is a linear tetra pyrrole B B. Contains ferric iron C C. End product of heme degradation D D. Essential for far digestion and absorption

44. BbA differs from HbF in that:

A A. HbA has only alpha chains B B. HbF cannot bind ro 2,3-BPG C C. HbF can bind on! 2 molecules of oxygen D D. HbA is alkali resistant

45. Met-hemoglobinemia is found in all the following conditions, except:

A A. Ingestion of nitrites B B. Carbon monoxide poisoning C C. Presence of Hb:\ r D D. Poisoning by aniline dyes

46. All the following are true about carboxyhemoglobin, except:

A A. CO binds to ferrous iron to form carboxyhemoglobin. B B. CO has more affinity for Hb than oxygen C C. Oxygen dissociation curve is shifted to right. D D. Cannot be convened back to deoxy-Hb

47. One deciliter (100 mL) of blood with 15 grams of hemoglobin can carry how much oxygen?

A A. 7.5 mL of oxygen B B. 15 ml of oxygen C C. 20 ml of oxygen D D. 30 ml of oxygen

48. Which factor causes a shift in the ODC (oxygen dissociation curve) to left?

A A. High pO2 B B. low pH C C. Low pO2 D D. High temperature

49. All the following manifestations are seen in sickle cell anemia (HbS disease), except:

A A. Pain and swellings in joints B B. Hemolytic anemia C C. Sickled cells in peripheral circulation D D. Inclusion bodies in RBCs

Sign in required