Two groups investigate the effect of pH on amylase activity. They use equal quantities of starch and the same method.
Table
| pH | Mean time for starch to disappear in group P / s | Mean time for starch to disappear in group Q / s |
|---|---|---|
| 5 | 120 | 60 |
| 6 | 80 | 40 |
| 7 | 40 | 20 |
| 8 | 80 | 40 |
Group Q accidentally used a more concentrated amylase solution.
Which conclusion remains supported by both sets of results?
At every pH tested, group P has twice the reaction rate of group Q.
Changing pH from 5 to 6 doubles the reaction rate in each group.
Of the pH values tested, pH 7 gives the greatest rate in each group.
Changing pH from 7 to 8 doubles the reaction rate in each group.
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.