An investigator is measuring the rate of an enzyme-controlled reaction where catalase decomposes hydrogen peroxide, releasing oxygen gas. The volume of oxygen gas released is recorded over 5 minutes at two different temperatures.
The table below shows the results of this investigation:
| Temperature (∘C^{\circ}\text{C}∘C) | Volume of oxygen gas released in 5 minutes (cm3\text{cm}^3cm3) | ||||
|---|---|---|---|---|---|
| Trial 1 | Trial 2 | Trial 3 | Mean | Range | |
| 20 | 18 | 15 | 18 | 17 | 15–18 |
| 40 | 41 | 37 | 42 | ......... | 37–42 |
Calculate the missing mean volume of oxygen gas released at 40∘C40^{\circ}\text{C}40∘C to complete the table. Show your working.
Identify which variable (Temperature or Volume of oxygen gas released) should be plotted on the x-axis.
Explain how knowing the range of the trials helps the investigator when drawing conclusions from a graph of these results.
44 exam-style questions on OCR GCSE Biology Practical skills. Each one has a worked solution and a mark scheme showing where the marks go.