Question

Choose correct options regarding enzyme with their respective substrates: A. Monoamine oxidase: Catecholamines B. HMG CoA reductase: Hypoxanthine xanthine C. Acetyl choline esterase: Acetyl choline D. Dihydropteroate synthase: Para-amino benzoic acid (PABA) E. Vitamin K epoxy reductase: Amphetamine Choose the correct answer from the options given below:

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

Hint:

Acetylcholinesterase is explicitly named after its substrate, acetylcholine (C), which helps you easily narrow down the choices.

Answer 1

The Correct Option is B

Step 1: Concept Enzymes display absolute or structural specificity toward particular chemical arrangements on substrate molecules, allowing them to regulate distinct steps in biochemical pathways.

Step 2: Meaning Evaluating the structural pairings between the listed enzymes and their true cellular substrate molecules.

Step 3: Analysis * Statement A: Monoamine oxidase (MAO) is a mitochondrial enzyme that metabolizes and breaks down monoamine neurotransmitters, including catecholamines like epinephrine and dopamine $\rightarrow$ Correct. * Statement B: HMG-CoA reductase acts on HMG-CoA during cholesterol synthesis, not on purine salvage metabolites like hypoxanthine. * Statement C: Acetylcholinesterase is a specialized synaptic enzyme that rapidly hydrolyzes the neurotransmitter acetylcholine into choline and acetate $\rightarrow$ Correct. * Statement D: Dihydropteroate synthase combines para-aminobenzoic acid (PABA) with pteridine diphosphate during bacterial folate synthesis $\rightarrow$ Correct. * Statement E: Vitamin K epoxide reductase acts on oxidized vitamin K forms to recycle them, having no direct biochemical connection to amphetamine molecules.

Step 4: Conclusion The combinations that are chemically accurate are A, C, and D, which corresponds to option B. Final Answer: (B)