Question

Enzymes are classified on the basis of reaction they catalyze. Which of the following are correct combinations? A. Oxidoreductase: Oxidation-reduction reaction B. Transferases: Transfer of group C. Hydrolases: Catalyze hydrolysis D. Lyases: Addition of group E. Ligases: Catalyze inter-conversion of group Choose the correct answer from the options given below:

• A. A and B only \
• B. A, B and C only \
• C. D and E only \
• D. C and D only

Hint:

Remember the classic classification acronym: OTH LIL (Oxidoreductase, Transferase, Hydrolase, Lyase, Isomerase, Ligase) to keep their definitions straight.

Answer 1

The Correct Option is B

Step 1: Concept The International Enzyme Commission classifies all enzymes into six primary functional categories based on the specific type of chemical reaction they catalyze.

Step 2: Meaning The primary classification code (EC number) relies on the specific structural transformation that occurs during the enzymatic reaction.

Step 3: Analysis * Category A (Oxidoreductases): Catalyze oxidation-reduction reactions where electrons are transferred from a donor to an acceptor molecule $\rightarrow$ Correct. * Category B (Transferases): Catalyze the transfer of a functional group (such as a methyl, phosphate, or acetyl group) from one molecule to another $\rightarrow$ Correct. * Category C (Hydrolases): Catalyze the cleavage of chemical bonds by adding water molecules $\rightarrow$ Correct. * Category D (Lyases): Catalyze the removal of groups to form double bonds, or the addition of groups across double bonds, rather than serving as general group addition enzymes. * Category E (Ligases): Catalyze the joining of two molecules using energy from ATP hydrolysis, whereas the inter-conversion of groups within a single molecule is catalyzed by Isomerases.

Step 4: Conclusion The combinations that are completely accurate according to official enzyme commission rules are A, B, and C, matching option B. Final Answer: (B)