Question

Match List-I with List-II

List-I (Reaction catalyzed/Name of the enzyme) & List-II (Class of enzyme)
(A) Formation and removal of carbon-carbon double bonds & (I) Ligase
(B) Amino acyl $-$ tRNA synthetase & (II) Hydrolase
(C) Transamination & (III) Lyase
(D) Removal of fatty acids from triglycerides & (IV) Transferase

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

Hint:

To remember the six major enzyme classes in order of their EC classification numbers, use the mnemonic: Over The Hill Lies Interesting Land (Oxidoreductase, Transferase, Hydrolase, Lyase, Isomerase, Ligase).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The International Union of Biochemistry and Molecular Biology (IUBMB) classifies enzymes into six major classes based on the type of reaction they catalyze: Oxidoreductases (EC 1), Transferases (EC 2), Hydrolases (EC 3), Lyases (EC 4), Isomerases (EC 5), and Ligases (EC 6).

Step 2: Detailed Explanation:
Let us analyze each reaction in List-I to determine its enzyme class in List-II:
1. Formation and removal of carbon-carbon double bonds: Enzymes that catalyze the addition of groups to double bonds, or the reverse reaction where double bonds are formed by removing groups without hydrolysis or oxidation, are classified as Lyases (EC 4).
An example is fumarase. Thus, (A) matches with (III).
2. Amino acyl-tRNA synthetase: This enzyme catalyzes the covalent attachment of an amino acid to its corresponding tRNA molecule, coupled with the hydrolysis of ATP to AMP and pyrophosphate.
Enzymes that join two molecules together coupled with the cleavage of a high-energy phosphate bond are classified as Ligases (EC 6). Thus, (B) matches with (I).
3. Transamination: This reaction involves transferring an amino group from an amino acid to a keto acid, typically catalyzed by aminotransferases.
Enzymes that transfer functional groups from one substrate to another are classified as Transferases (EC 2). Thus, (C) matches with (IV).
4. Removal of fatty acids from triglycerides: This reaction is catalyzed by lipases, which cleave ester bonds in triglycerides using water.
Enzymes that catalyze the cleavage of bonds by adding water are classified as Hydrolases (EC 3). Thus, (D) matches with (II).
This gives the match combination: (A) - (III), (B) - (I), (C) - (IV), (D) - (II).

Step 3: Final Answer:
The correct matching sequence is (A) - (III), (B) - (I), (C) - (IV), (D) - (II), which corresponds to option (B).