Biochemistry Paper-2 (Main), 2022 MBBS Batch ABVMU Lucknow

ATAL BIHARI VAJPAYEE MEDICAL UNIVERSITY, LUCKNOW
MBBS DEGREE EXAMINATION - 1st PROFESSIONAL - NOV - 2023
BIOCHEMISTRY - PAPER - II

SECTION A - Multiple Choice Questions (MCQs)

PAPER CODE: 2312130003
SET: D

Note:

• Choose one correct answer in the OMR sheet provided.

• No overwriting should be done.

1. End product of purine metabolism in non-primate mammals is -

a) Urea
b) Allantoin
c) Uric acid
d) Ammonia

2. Wobble hypothesis explains which of the following concepts of the genetic code?

a) Non-punctuated
b) Degeneracy
c) Universal
d) Unambiguous

3. Sickle cell anemia is the clinical manifestation of homozygous genes for an abnormal hemoglobin molecule. The mutation in the β-chain is known to produce a single amino acid change. The most likely mechanism for this mutation is?

a) Crossing over
b) Single-base substitution (point mutation)
c) Two-base insertion
d) Nondisjunction

4. An infant with severe vomiting who was misdiagnosed as a case of hypertrophic pyloric stenosis is being screened for metabolic disorders. Screening reveals hyperphenylalaninemia. On ordering an enzyme study, you would include all of the following enzymes except:

a) Dihydropteridine synthase
b) GTP cyclohydrolase
c) Phenylalanine hydroxylase
d) Dihydropteridine reductase

5. A 40-year-old man with a large dirty wound on his knee and abrasions on his palms presents to the casualty. He does not remember the last time he received a tetanus toxoid injection and was thus given tetanus immunoglobulin. Which of the following is false about this type of immunity?

a) Long-lasting
b) No negative phase
c) Acquired immediately
d) Memory is absent

6. Hartnup disease is characterized by impaired absorption of which amino acid?

a) Histidine
b) Arginine
c) Lysine
d) Proline

7. A deficiency of copper affects the formation of normal collagen by reducing the activity of:

a) Lysyl hydroxylase
b) Glucosyl transferase
c) Prolyl hydroxylase
d) Lysyl oxidase

8. Which one of the following post-transcriptional modifications requires vitamin K?

a) ADP-ribosylation of histones
b) Hydroxylation of proline and lysine in collagen
c) Methylation of calmodulin
d) Carboxylation of glutamate in prothrombin

9. In which of the following porphyria cutanea hypersensitivity is not observed?

a) Congenital erythropoietic porphyria
b) Hereditary coproporphyria
c) Variegate porphyria
d) Acute intermittent porphyria

10. Xanthurenic aciduria is seen in the deficiency of:

a) Pyridoxine
b) Pantothenic acid
c) Niacin
d) Thiamine

11. The metal found in xanthine oxidase enzyme is:

a) Molybdenum
b) Manganese
c) Magnesium
d) Copper

12. Apart from occurring in nucleic acids, pyrimidines are also found in:

a) Flavin mononucleotide
b) Thiamine
c) Theophylline
d) Theobromine

13. All of the following are examples of housekeeping genes, except:

a) Beta-galactosidase
b) RNA polymerase
c) Ribosomal protein genes
d) rRNA genes

14. Chromosomal end replication is done by:

a) Telomerase
b) Polymerase-α
c) Polymerase-ε
d) Primase

15. Intron is not found in which DNA?

a) B-DNA
b) Nuclear DNA
c) Z-DNA
d) Mitochondrial DNA

16. Which amino acid is not responsible for the synthesis of creatine, a crucial molecule for energy metabolism in muscle cells?

a) Glycine
b) Methionine
c) Arginine
d) Glutamine

17. A patient's plasma has high levels of interferon-beta. He most likely has an infection due to:

a) Fungi
b) Mycoplasma
c) Virus
d) Bacteria

18. The promoter sequence in transcription is found on:

a) Antisense strand
b) Minus strand
c) Sense strand
d) Coding strand

19. Serum AFP is a tumor marker for:

a) Liver
b) Tongue
c) Ovary
d) Testis

20. Immunological synapse is essential for the activation of:

a) T-cells
b) Eosinophils
c) B-cells
d) Neutrophils

ATAL BIHARI VAJPAYEE MEDICAL UNIVERSITY, LUCKNOW

MBBS DEGREE EXAMINATION - 1st PROFESSIONAL - NOV - 2023
BIOCHEMISTRY - PAPER - II

TIME: 3 Hrs

Max. Marks: 100 Marks (80 Theory + 20 MCQs)

NOTE:

• Attempt all questions.

• This question paper consists of two sections: Section A - Multiple Choice Questions and Section B - Theory Questions.

• Both sections have different paper codes. Write the correct paper code on the respective sheet.

• Write the correct MCQ paper set on the OMR sheet.

• Answer MCQs on the provided OMR sheet and theory questions in the provided answer booklet.

SECTION B - THEORY QUESTIONS

PAPER CODE: 2312130003

Q.1 Long Answer Question (15 MARKS)

• What are the major components of extracellular matrix and mention their functional properties? (5 marks)

• Explain the salient features of the structural organization of collagen. (5 marks)

• Mention the major disorders associated with abnormalities in collagen structure and function. (5 marks)

Q.2 Clinical Case Scenario-based Structured Question (15 MARKS)

A 45-year-old male came to the OPD with complaints of fever, nausea, and vomiting for the past 10 days. On examination, he was found to have yellowish discoloration of eyes (icterus). Though there was no pallor or cyanosis, the laboratory findings are as follows:

Parameter Unit Normal Range

Albumin 4.9 g/dl 3.5 - 5.5

Total protein 7.9 g/dl 6.0 - 8.5

Creatinine 0.7 mg/dl 0.4 - 1.4

Urea 38 mg/dl 10 - 45

Total Bilirubin 10.5 mg/dl 0.3 - 1.2

Direct Bilirubin 7.2 mg/dl 0.0 - 0.2

SGOT 265 U/L 0 - 50

SGPT 920 U/L 0 - 50

Questions

1. In the given scenario, which type of Jaundice does the patient have? (1 mark)

2. Discuss the bilirubin synthesis. (2 marks)

3. Discuss the metabolism of bilirubin. (3 marks)

4. Discuss a diagnostic workup of a patient with jaundice. (4 marks)

5. What is the De Ritis ratio? Explain in detail in reference to the above case. (2 marks)

6. Differentiate between conjugated and unconjugated hyperbilirubinemia. (3 marks)

Q.3 Short Note Question (Approx 500 Words) (5 × 6 = 30 MARKS)

1. Discuss metabolism of Phenylalanine. Name various inborn errors of metabolism associated with its pathway. (6 marks)

2. Describe and discuss the commitment to lifelong learning, an important part of physician growth. (6 marks)

3. Describe Recombinant DNA technology. Discuss its applications in the medical field. (6 marks)

4. Discuss the structure and functions of Hemoglobin. (6 marks)

5. Describe factors affecting the binding of oxygen to hemoglobin. (6 marks)

6. Discuss the Classical Complement Pathway in brief. (6 marks)

Q.4 Short Answer Questions (Within 100 Words) (5 × 4 = 20 MARKS)

1. Discuss Maple Syrup Urine Disease. (4 marks)

2. Explain why serum from multiple myeloma patients shows a sharp band on protein electrophoresis. (4 marks)

3. Differences between humoral and cell-mediated immunity. (4 marks)

4. Discuss post-translational modifications. (4 marks)

5. Give a schematic representation of the Urea cycle. (4 marks)

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