Enzyme Specificity Defined by Reaction Selectivity

Steps:

• Define specificity: Enzymes catalyze only specific substrates or reactions due to their active site structure.
• Analyze the reaction: Maltase targets maltose hydrolysis to glucose, indicating narrow action.
• Evaluate choices: Identify which option directly addresses limited reaction scope versus general traits.
• Select D: It matches specificity by limiting reactions catalyzed.

Why D is correct:

• Enzyme specificity, per biochemical definition, means an enzyme accelerates only select reactions matching its substrate (e.g., maltase acts solely on maltose, not other sugars).

Why the others are wrong:

• A: States general enzyme traits (catalyst, protein) without addressing reaction limits.
• B: Describes pH optimum for activity, unrelated to substrate selectivity.
• C: Explains general catalytic role (lowering activation energy) for any reaction it performs.

Final answer: D