Glucose moves from the contents of the small intestine into the blood across the villi.
The table shows glucose concentrations measured at two times after a meal.
| Time after the meal in minutes | Glucose concentration in the intestinal contents in mmol dm−3\mathrm{mmol\,dm^{-3}}mmoldm−3 | Glucose concentration in the blood arriving at the villi in mmol dm−3\mathrm{mmol\,dm^{-3}}mmoldm−3 |
|---|---|---|
| 20 | 20 | 5.0 |
| 50 | 11 | 5.0 |
Calculate the percentage of the glucose concentration difference at 20 minutes that has been lost by 50 minutes.
102 exam-style questions on Edexcel GCSE Biology 8.1 Exchange surfaces and diffusion, covering 8.1.1 Introduction to exchange and transport, 8.1.2 Alveoli adapted for gas exchange, 8.1.3 Factors affecting rate of diffusion, and 8.1.4 Rate of diffusion using Fick's law. Each one has a worked solution and a mark scheme showing where the marks go.