Pieces of ileum tissue were used to measure the rate of glucose uptake under three conditions. The results are shown in arbitrary units.
| Condition | Glucose uptake / arbitrary units |
|---|---|
| Sodium ions present | 100 |
| Sodium ions absent | 12 |
| Sodium ions present, plus a respiratory inhibitor | 15 |
Calculate the percentage decrease in glucose uptake when the sodium ions are removed.
[1]
Explain why removing the sodium ions reduces glucose uptake.
[2]
Explain why the respiratory inhibitor reduces glucose uptake even though sodium ions are present.
[2]