A culture of cells carries out aerobic respiration. Substances X and Y are each one of glucose, oxygen, carbon dioxide or water. Their amounts change only because of aerobic respiration.
| substance | amount at the start in mmol | amount after 5 minutes in mmol |
|---|---|---|
| X | 0.95 | 0.70 |
| Y | 2.10 | 0.60 |
Calculate the ratio of the amount of Y used to the amount of X used. Use this ratio to identify X and Y.
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.