A second team measured catalase activity at 10 mM H2O2 across a pH range from 4 to 10. Reactions ran for 30 seconds at 25 degrees C. Each bar shows mean rate (mL O2/s).
What does the pattern suggest about catalase?
- A
It functions equally well across all tested pH values.
- B
Activity increases linearly with pH.
- C
It functions only in acidic environments.
- Dcheck_circle
Its optimal pH is near 7, with sharply reduced activity at extreme pH.
Explanation
Activity peaks at pH 7 and falls off on either side. Extreme pH disrupts the active-site shape and ionization of side chains, lowering catalytic efficiency.