Disorders of Nucleotide Metabolism and MCQs GPAT, NEET UPSC, Pharmacist, CSIR NET and Nursing Exam

Disorders of Nucleotide Metabolism and MCQs GPAT, NEET UPSC, Pharmacist, CSIR NET and Nursing Exam

Below are the Disorders of Nucleotide Metabolism

Gout

It is a metabolic disorder and is associated with increase level of uric acid in the serum due to less excretion and more production

This disease is associated with hyperuricemia

It is characterized by deposition of urate crystals in the soft tissue which affects the joints and then leads to painful arthritis. Deposition of excess urate (kidney tubules) leads to kidney failure.

Gout is divided in two types:

  • Primary gout:- It is due to the deficiency of the enzymes of de-novo synthesis and salvage pathway.
  • Secondary gout:- It is due to excess degradation of purine nucleotide into uric acid mainly in diseases like cancer, trauma, psoriasis etc. decrease in uric acid elimination is due to reduced glomerular filtration rate.

Causes:- Defective nucleotide metabolism, excess uric acid in blood, obesity, over consumption of sea food, certain diseases like heart diseases.

Treatment:- It can be cured by nutritional or drug therapy.

  • Avoid food containing rich in purine like coffee, tea
  • Drugs like allopurinal. This drug is an analog of hypoxanthine which inhibits the xanthine oxidase which further decreases the formation of uric acid and increases the excretion of soluble xanthine and hypoxanthine.

Orotic aciduria

It is a pyrimidine nucleotide disorder. It is a hereditary defect in the enzymes that catalyzes the pyrimidine nucleotide synthesis; mainly UMP-synthase. UMP synthetase is a multi-enzyme and has two main activity:

  • Phosphoribosyl transferase (PT)
  • Decarboxylase (DC)

Orotic aciduria is of types

  • Type-1: deficiency of PT and DC
  • Type-2: deficiency of DC

So the deficiency of UMP and other pyrimidine nucleotide result in the inhibition of DNA and RNA which further leads to megaloblastic anemia and growth retardation. This increases the excretion of orotate in urine.

Causes:- Decreased ability to synthesize pyrimidine and deficiency of enzymes of nucleotide synthesis

Treatment:- Uridine triacetate

Reye’s syndrome

Due to the severe damage of mitochondria, it is unable to utilize the carbomyl phosphate generated through urea cycle. Therefore it is diverted for pyrimidine synthesis; this leads to over production of orotate and increases the excretion of orotate in urine. This is known as secondary aciduria.

Causes:- The cause is not certain but some of the time it happens due to excess consumption of aspirin tablets

Treatment:- Anti-ematic, diuretics, ammonia detoxifying agents and anticonvulsants.

Multiple Choice Questions (MCQs)

1. What is gout?
A. Increased ammonia serum level

B. Decreased ammonia serum level

C. Increased uric acid serum level

D. Both B and C

2. Gout is associated with which of the following-
A. Hyperuricemia

B. Hypouricemia

C. Hyperthyroidism

D. Hypothyroidism

3. What is the cause of primary gout?
A. Deficiency of enzymes for the synthesis purine nucleotide
B. Excess degradation of purine nucleotide
C. Both
D. None

4. What is the cause of secondary gout?
A. Deficiency of enzymes for purine nucleotide
B. Excess degradation of purine nucleotide
C. Both
D. None

5. What is the reason for the decreased elimination of uric acid from the body?
A. Increased glomerular filtration rate

B. Deficiency of UMP-synthetase

C. Decreased glomerular filtration rate

D. None of the above

6. Orotic aciduria is which type of disorder?
A. Purine nucleotide disorder

B. Pyrimidine nucleotide disorder

C. Nucleic acid disorder

D. All of the above

7. Reye’s syndrome is which type of disorder?
A. Purine nucleotide disorder

B. Pyrimidine nucleotide disorder

C. Nucleic acid disorder

D. All of the above

8. Match the following-

A. Primary gout 1. excess uric acid in blood

B. Secondary gout 2. over consumption of aspirin tablets

C. Cause of gout 3. Excess degradation of purine nucleotide

D. Cause of Raye’s syndrome 4. deficiency of enzymes participating in                                                                     formation of purine nucleotide

9. Why is type-1 orotic aciduria caused?
A. Deficiency of PT

B. Deficiency of DC

C. Deficiency of PT and DC

D. None of the above

10. Why is type-2 orotic aciduria caused?
A. Deficiency of PT

B. Deficiency of DC

C. Deficiency of PT and DC

D. None of the above

11. Which of the food item is rich in purine?
A. Coffee

B. Tea

c. Alcohol beverages

D. All of the above

12. Which of the following statement is NOT true?

A. Defective PRPP synthetase causes hyperuricemia

B. Secondary gout causes decreased elimination of uric acid in urine

C. Deficiency of UMP causes megaloblastic anemia

D. Orotic aciduria is of two types
13. Orotic aciduria is caused due to the defect in which enzyme?
A. UMP-synthetase

B. Pospho-fructokinase

C. Both

D. None

14. In Reye’s syndrome, which component of cell is damaged?
A. Nucleus

B. Ribosome

C. Cytosol

D. None of the above

15. What is the activity of UMP-synthetase enzyme?
A. Decarboxylase

B. Phosporibosyl transferase

C. Both

D. None

ANSWERS:-
1. Increased uric acid serum level
2. Hyperuricemia
3. Deficiency of enzymes for the synthesis of purine nucleotide
4. Excess degradation of purine nucleotide
5. Decreased glomerular filtration rate
6. Pyrimidine nucleotide disorder
7. Pyrimidine nucleotide disorder
8. A – 4 B – 3 C – 1 D – 2
9. Deficiency of PT and DC
10. Deficiency of DC
11. All of the above
12. Defective PRPP synthetase causes hyperuricemia
13. UMP-synthetase
14. None of the above
15. Both

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; 4th edition; page no:- 332-335

Leave a Reply

Your email address will not be published. Required fields are marked *

one × five =

×
Free Video Lectures of Pharmacy Exams
Apply now

Developed By Connect Globes