Choose the correct answer from the options given below:

1. (A)–(III); (B)–(I); (C)–(II); (D)–(IV)
2. (A)–(I); (B)–(III); (C)–(II); (D)–(IV)
3. (A)–(III); (B)–(II); (C)–(IV); (D)–(I)
4. (A)–(II); (B)–(III); (C)–(I); (D)–(IV)
   

   Enzyme Classes Matching: Oxidoreductases, Transferases, Lyases, Ligases Reactions

   Enzyme classes are categorized by the biochemical reactions they catalyze in metabolism and cellular processes. This SEO guide solves Q.54 matching question with the correct answer and detailed analysis of all options.

   Correct Answer

   The correct option is (A)–(II); (B)–(III); (C)–(I); (D)–(IV). Oxidoreductases handle electron transfers, transferases move functional groups, lyases break bonds via elimination, and ligases form bonds through condensation.

   Enzyme-Reaction Matches

   • Oxidoreductases (A) – Transfer of electrons (hydride ions or H atoms) (II): Catalyze redox reactions like dehydrogenases transferring H atoms or electrons between substrates.

   • Transferases (B) – Group transfer reaction (III): Move functional groups (e.g., phosphate, amino) from donor to acceptor molecules, like kinases.​

   • Lyases (C) – Cleavage of C–C, C–O, C–N or other bonds by elimination (I): Break bonds without hydrolysis/oxidation, creating double bonds or rings, e.g., aldolase.​

   • Ligases (D) – Formation of C–C, C–S, C–O and C–N bonds by condensation reaction (IV): Join molecules using ATP energy, like DNA ligase forming phosphodiester bonds.​

   Incorrect Options Explained

   • Option 1: (A)–(III); (B)–(I); (C)–(II); (D)–(IV) Wrong: Oxidoreductases not group transfer; lyases not electron transfer.

   • Option 2: (A)–(I); (B)–(III); (C)–(II); (D)–(IV) Wrong: Oxidoreductases catalyze redox, not elimination cleavage.

   • Option 3: (A)–(III); (B)–(II); (C)–(IV); (D)–(I) Wrong: Lyases don’t form bonds (that’s ligases); oxidoreductases not group transfer.

   Enzyme Classification Overview

   Six main classes (EC 1-6) standardize nomenclature: EC1 oxidoreductases, EC2 transferases, EC4 lyases, EC6 ligases. This system aids biochemistry research and drug design.​