Question

Match List-I with List-II

Choose the correct answer from the options given below:

• (A) - (I), (B) - (II), (C) - (IV), (D) - (III)
• (A) - (II), (B) - (I), (C) - (III), (D) - (IV)
• (A) - (III), (B) - (II), (C) - (IV), (D) - (I)
• (A) - (III), (B) - (IV), (C) - (I), (D) - (II)

Hint:

To solve this quickly, associate Acetyl-CoA carboxylase with biotin (D - IV), and Serine hydroxymethyl transferase with pyridoxal phosphate (C - III), which instantly singles out option (B).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Many enzymes require non-protein helper molecules called cofactors or prosthetic groups to carry out their biological activities.

Step 2: Detailed Explanation:
Let us match each enzyme with its required cofactor:
(A) Nitrogenase requires a specialized iron-molybdenum cofactor (FeMoco) for nitrogen fixation, which contains an organic homocitrate component (II) essential for stabilizing the metal cluster.
(B) Nitrite reductase requires siroheme (I), an iron-containing porphyrinoid cofactor that transfers electrons to reduce nitrite to ammonium.
(C) Serine hydroxymethyl transferase is a PLP-dependent enzyme that uses pyridoxal phosphate (III) to catalyze the reversible conversion of serine to glycine.
(D) Acetyl-CoA carboxylase is a biotin-dependent enzyme (IV) that uses its biotin prosthetic group to transfer carboxyl groups during fatty acid synthesis.
This matching sequence is: (A) - (II), (B) - (I), (C) - (III), (D) - (IV).

Step 3: Final Answer:
This sequence corresponds to option (B).