Two equal samples of living insect cells, X and Y, are supplied with glucose.
At time 0, a chemical that stops cellular respiration is added to sample Y. The chemical does not directly affect membrane transport proteins.
| Time in minutes | ATP concentration in sample X in mmol dm⁻³ | ATP concentration in sample Y in mmol dm⁻³ |
|---|---|---|
| 0 | 2.4 | 2.4 |
| 2 | 2.3 | 1.7 |
| 4 | 2.4 | 1.0 |
| 6 | 2.3 | 0.4 |
After 6 minutes, both samples are placed in solutions where the concentration of mineral ions is lower than the concentration inside the cells.
Calculate the percentage decrease in ATP concentration in sample Y between 0 minutes and 6 minutes.
Give your answer to three significant figures.
Explain the pattern in ATP concentration and which sample would take up mineral ions faster after 6 minutes.
98 exam-style questions on Edexcel GCSE Biology 8.3 Respiration, covering 8.3.1 Aerobic and anaerobic respiration. Each one has a worked solution and a mark scheme showing where the marks go.