Biological Catalyst Specificity

Steps:

• Disaccharides hydrolyze slowly in acid without catalyst.
• Catalyst accelerates sucrose and maltose hydrolysis but not lactose.
• This selective speeding up indicates targeted action on specific substrates.
• Biological catalysts (enzymes) exhibit substrate specificity.

Why C is correct:

• Enzymes show specificity by binding and catalyzing only compatible substrates, like sucrase for sucrose and maltase for maltose, per lock-and-key model.

Why the others are wrong:

• A: Catalysts lower activation energy to speed reactions, not increase it.
• B: Lactose hydrolysis remains uncatalyzed, so mechanism unchanged from acid-only process.

Final answer: C