Cells lining kidney tubules reabsorb glucose from the fluid that will become urine.
A scientist measured the initial glucose concentrations in the tubule fluid and inside the cells.
| Location | Glucose concentration in mg per cm³ |
|---|---|
| Tubule fluid | 0.60 |
| Inside the cells | 1.80 |
The scientist then measured glucose uptake by equal masses of kidney tubule tissue. Each sample was kept at the same temperature. The chemicals used did not damage the cell membranes.
| Treatment | Rate of glucose uptake in µmol per gram of tissue per hour |
|---|---|
| No chemical added | 6.8 |
| Chemical that reduces respiration added | 1.4 |
| Chemical that blocks carrier proteins added | 0.9 |
Explain how the concentration data and the uptake results provide evidence that glucose is taken into the cells by active transport.
A patient has fewer mitochondria in the cells lining the kidney tubules.
Explain how this is likely to affect the amount of glucose remaining in the patient's urine.
140 exam-style questions on AQA GCSE Biology 1.3 Transport in cells, covering 1.3.1 Diffusion, 1.3.2 Osmosis, and 1.3.3 Active transport. Each one has a worked solution and a mark scheme showing where the marks go.