Question:
Selenocysteine is associated with which of the following?
Selenocysteine is associated with which of the following?
Show Hint
Think of the selenoenzyme that converts T4 to T3.
Updated On: Jun 24, 2026
- Carbonic anhydrase
- Catalase
- Deiodinase
- Transferase
Show Solution
Verified By Collegedunia
The Correct Option is C
Solution and Explanation
Step 1: Selenocysteine is regarded as the 21st amino acid. It is structurally like cysteine but has selenium in place of the sulfur atom, and it sits at the active site of certain redox enzymes.
Step 2: The selenoenzymes that use a selenocysteine residue include glutathione peroxidase, thioredoxin reductase and the iodothyronine deiodinases, which convert thyroxine (T4) to the active triiodothyronine (T3).
Step 3: Among the options, only deiodinase is a selenocysteine-containing enzyme, so option 3 is correct.
Step 4: Carbonic anhydrase is a zinc enzyme, catalase is a heme (iron) enzyme, and transferase is a generic enzyme class that does not require selenocysteine. Hence options 1, 2 and 4 are wrong.
Step 2: The selenoenzymes that use a selenocysteine residue include glutathione peroxidase, thioredoxin reductase and the iodothyronine deiodinases, which convert thyroxine (T4) to the active triiodothyronine (T3).
Step 3: Among the options, only deiodinase is a selenocysteine-containing enzyme, so option 3 is correct.
Step 4: Carbonic anhydrase is a zinc enzyme, catalase is a heme (iron) enzyme, and transferase is a generic enzyme class that does not require selenocysteine. Hence options 1, 2 and 4 are wrong.
Was this answer helpful?
0
0
Top NEET PG Biochemistry Questions
- Which of the following clotting factors is needed for gamma-glutamyl carboxylase?
- A patient presented with diarrhea, dermatitis, and dementia. Which of the following vitamin deficiencies would you suspect in this patient?
- A young boy presents to the OPD with hypoglycemia and muscle cramps, on exertion or while playing. Then he becomes normal after resting for a while. These episodes are recurrent after a period of activity. He has decreased serum lactate and glucose levels. Which of the following diseases is he most likely to be suffering from?
- A family consumes only polished rice. Which of the following combinations of vitamin deficiency and enzymatic defect will be present in this family?
- A chronic alcoholic patient presented to the casualty with confusion, ataxia, and painful eye movements. What could be the vitamin deficiency seen in this patient?
View More Questions
Top NEET PG Questions
- A patient hailing from Delhi presents with fever, arthralgia, and extensive petechial rash for 3 days. Lab investigations revealed a hemoglobin of 9 g/ dL, a white blood cell count of 9000 cells/mm3, a platelet count of 20000 cells/mm3, and a prolonged bleeding time. The clotting time was normal. What is the most likely diagnosis?
- Which of the following statements is true about Trichomonas vaginalis?
- A lady from West Rajasthan presented with an ulcer surrounded by erythema on the right leg. Microscopy of the biopsy from the edge of the ulcer showed organisms with dark staining nuclei and kinetoplast. What is the most likely causative agent?
- A child presents with a fever and a rash. Urine examination showed cells with owl's eye appearance. What is the most likely diagnosis?
- Infection with Clonorchis sinensis is associated with an increased risk of__?
View More Questions