Cells from the lining of the small intestine take up an amino acid against its concentration gradient.
A scientist places equal masses of these cells in three containers. Each container receives glucose continuously, but oxygen is supplied at a different rate. All other conditions are kept the same.
| Container | Rate of oxygen supplied in μmol min−1\mathrm{\mu mol\,min^{-1}}μmolmin−1 | Rate of oxygen used in μmol min−1\mathrm{\mu mol\,min^{-1}}μmolmin−1 | Rate of amino acid uptake in μmol min−1\mathrm{\mu mol\,min^{-1}}μmolmin−1 |
|---|---|---|---|
| A | 0.30 | 0.24 | 0.50 |
| B | 0.60 | 0.47 | 0.96 |
| C | 0.90 | 0.48 | 0.98 |
Explain the results, including how the rate of amino acid uptake would be affected if a fourth container received glucose but no oxygen.
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.