Catabolism of Hemoglobin and MCQs For Pharmacist, GPAT, NEET, GATE and CSIR NET Exams

After 120 days, RBCs are degraded by reticuloendothelial (RE) system, mainly in liver and spleen. Firstly, hemoglobin is dissociated into heme and globin.

Fate of Globin

The globin may be reutilized for the formation of hemoglobin or degraded to the individual amino acids. The amino acids than undergo their own metabolism, and also participates in fresh globin synthesis.

Degradation of Heme

The catabolism of heme is carried out in small fractions of cells by a complex enzyme system known as heme oxygenase. It occurs in the presence of NADPH and oxygen. Ferric ion, CO and a green pigment known as biliverdin are released. Biliverdin is then converted to red orange pigment known as bilirubin. Bilirubin and its derivatives are collectively known as bile pigments.

The daily bilirubin formation in the body is 250-350 mg. this is yielded not only from hemoglobin but from ineffective erythropoiesis and also from various other heme proteins like cytochrome P₄₅₀.

Multiple Choice Questions (MCQs)

1. What is the average life span of RBCs?
A. 1 week
B. 1 month
C. 2 years
D. 4 months

2. Where do RE system takes place?
A. Spleen
B. Liver
C. Kidney
D. Both A and B

3. What happens to the globin part of hemoglobin after its dissociation?
A. Excreted through urine
B. Stored in liver
C. Degraded to its amino acid
D. None of the above

4. What is the complex enzyme system for the catabolism of heme called?
A. Heme dehydrogenase
B. Heme transferase
C. Heme oxygenase
D. Heme synthetase

5. What is the product released after catabolism of heme?
A. Biliverdin
B. Carbon mono-oxide
C. Ferric ion
D. All of the above

6. What is the color of bilirubin?
A. Green
B. Brown
C. Red-orange
d. Yellow-orange

7. What is the approximate formation of bilirubin in adults?
A. 150-220 mg
B. 50-70mg
C. 250-350 mg
D. 500-700 mg

8. Match the following substrate and its product-
A. Globin 1. Bilirubin
B. Heme 2. Biliverdin
C. Biliverdin 3. Amino acid

9. 1gm of hemoglobin yields how much of bilirubin?
A. 20mg
B. 25mg
C. 30mg
D. 35mg

10. What is the color of biliverdin?
A. Green
B. Brown
C. Red-orange
d. Yellow-orange

11. Complex enzyme system occurs aerobically or anaerobically?
A. Aerobically
B. Anaerobically
C. Both
D. None

12. Which of the following statement is NOT true?

A. Bilirubin is lipophilic in nature

B. Biliverdin reductase is a ATP dependent soluble enzyme

C. Albumin has 2 binding sites for bilirubin

D. Heme oxygenase enzyme produces biliverdin, ferrous ion and CO.
13. Which form of energy is required for the working of complex enzyme system?
A. ATP
B. ADP
C. NAD
D. None of the above

14. What are the sources that yield bilirubin other than hemoglobin?
A. Ineffective erythropoiesis
B. Cytochrome P450
C. Both
D. None

15. Fill in the blank- bilirubin is the most abundant ——-?
A. Lubricant
B. Astringent
C. Anti-oxidant
D. Antiseptic

ANSWERS-

1. 4 months
2. Both A and B
3. Degraded to its amino acid
4. Heme oxygenase
5. All of the above
6. Red orange
7. 250-350mg
8. A – 3 B – 2 C – 1
9. 35mg
10. Green
11. Aerobically
12. Biliverdin reductase is a ATP dependent soluble enzyme
13. None of the above
14. Both
15. Anti-oxidant

For More Standard and Quality Question Bank you can Join Our Test Series Programme for GPAT, NIPER JEE, Pharmacist Recruitment Exam, Drug Inspector Recruitment Exams, PhD Entrance Exam for Pharmacy

Participate in Online FREE  GPAT  TEST: CLICK HERE

  Participate in Online FREE  Pharmacist  TEST: CLICK HERE 

Participate in Online FREE  Drug Inspector  TEST: CLICK HERE 

Participate in CSIR NET JRF Mock Test

Participate GATE Mock Test

REFERENCE:- 1. Pankaja Naik- Biochemistry; 4^th edition; page no:- 316-317.

2. U. Satyanarayana, U. Chakrapani; Biochemistry; Elsevier; 4th edition; page no- 214-216.