Enzyme pH optima determine activity curve peaks

Steps:

• Enzyme P requires acidic conditions, so its activity peaks below pH 7.
• Enzyme Q has slightly alkaline optimum, so its activity peaks above pH 7 (around 8-9).
• Correct graph shows two curves: one peaking in acidic range, the other in alkaline range.
• Option B matches this with P's curve left of neutral and Q's right of neutral.

Why B is correct:

• Enzyme activity follows a bell-shaped curve peaking at optimum pH, per enzyme kinetics; B aligns P's acidic peak and Q's alkaline peak with this principle.

Why the others are wrong:

• A: Both curves peak in acidic range, ignoring Q's alkaline optimum.
• C: Curves peak at same neutral pH, not distinguishing acidic vs. alkaline.
• D: Q's curve peaks acidic, contradicting its slightly alkaline optimum.

Final answer: B