Enzyme activity peaks at optimal temperature

Steps:

• Recall that enzymes like amylase have an optimal temperature where reaction rate is highest.
• Rate increases with temperature up to the optimum due to more kinetic energy and collisions.
• Beyond optimum, rate decreases as enzyme denatures and active site changes shape.
• Identify graph showing rise to peak then sharp decline as correct for amylase.

Why B is correct:

• Matches enzyme kinetics: rate rises to optimum (~37°C for human amylase) then falls due to denaturation, per Arrhenius equation adapted for proteins.

Why the others are wrong:

• A shows linear increase, ignoring denaturation.
• C shows constant rate, defying temperature effects on collisions.
• D shows steady decline, typical of non-enzymatic reactions only.

Final answer: B