A student investigated the effect of temperature on the rate of starch breakdown by the enzyme amylase. The starch was mixed with amylase at different temperatures, and the time taken for starch to be completely broken down was recorded.
| Temperature (∘C^{\circ}\text{C}∘C) | Time taken for starch to be completely broken down (minutes) |
|---|---|
| 20 | 10 |
| 35 | 4 |
| 50 | 8 |
| 70 | Starch was still present after 15 minutes |
Explain why the starch was not broken down in the investigation at 70∘C70^{\circ}\text{C}70∘C.
44 exam-style questions on AQA GCSE Biology 2.2 Animal tissues, organs and organ systems, 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. Each one has a worked solution and a mark scheme showing where the marks go.