A student records the time for starch to disappear in four repeats at the same pH.
Table
| Repeat | Time / s |
|---|---|
| 1 | 42 |
| 2 | 44 |
| 3 | 82 |
| 4 | 46 |
Repeat 3 is identified as an anomalous result and is excluded when calculating the mean time.
The experiment is repeated under conditions that double the mean reaction rate. The same quantity of starch is used.
What time is predicted for the starch to disappear?
27 s27\,\mathrm{s}27s
22 s22\,\mathrm{s}22s
44 s44\,\mathrm{s}44s
88 s88\,\mathrm{s}88s
44 exam-style questions on Edexcel GCSE Biology 1.3 Enzymes, covering 1.3.1 Mechanism of enzyme action, 1.3.2 Denaturation of enzymes, 1.3.3 Factors affecting enzyme activity, and 1.3.4 Measuring energy in food by calorimetry. Each one has a worked solution and a mark scheme showing where the marks go.