An investigation was carried out on two protease enzymes, Enzyme A and Enzyme B, to see how pH affects their rate of reaction.

State the optimum pH for Enzyme B.
Enzyme A is found in the human stomach. Explain why Enzyme A is suited to working in the stomach.
Complete the sentences to explain why Enzyme B does not work at pH 11. 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 ______.
Practise AQA GCSE Biology 2.2 Animal tissues, organs and organ systems with exam-style questions for Foundation and Higher tier. 70 questions covering 2.2.1 The human digestive system, 2.2.2 The heart and blood vessels, 2.2.3 Blood, 2.2.4 Coronary heart disease: a non-communicable disease, 2.2.5 Health issues, 2.2.6 The effect of lifestyle on some non-communicable diseases, and 2.2.7 Cancer, matched to the AQA GCSE Biology (8461) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.