An investigation was carried out on two digestive protease enzymes, Enzyme P and Enzyme Q, to determine how pH affects their rate of reaction.

State the optimum pH for Enzyme Q.
Enzyme P is active in the human stomach. Explain why Enzyme P is highly suited to the environment of the stomach.
Complete the sentences to explain why Enzyme Q does not function at pH 11.5. Choose words from the following list:
The part of the enzyme that changes shape is the ______.
The change in shape means the enzyme cannot bind to the ______.