Temperature Optimum for Enzyme Activity

Steps:

• Enzymes like amylase function best at an optimal temperature, where reaction rate is highest.
• At low temperatures, activity is low, so much starch remains.
• Activity peaks at optimum temperature, minimizing remaining starch.
• Above optimum, enzyme denatures, reducing activity and increasing remaining starch.

Why C is correct:

• Graph C shows starch remaining high at low temperatures, lowest at optimum (~37°C for human amylase), then rising at high temperatures, matching enzyme denaturation principle.

Why the others are wrong:

• A: Linear decrease ignores denaturation rise.
• B: Steady decline overlooks optimal peak.
• D: Increase only reflects cold inactivity, misses optimum drop.

Final answer: C