A scientist tests two partially permeable membranes as models of the filtration barrier at the glomerulus. Membrane P models a healthy filtration barrier.
The same mixture is placed under the same pressure against each membrane. The table shows which components pass through each membrane into the collecting liquid.
| component of the mixture | passes through membrane P | passes through membrane Q |
|---|---|---|
| water and small dissolved molecules | yes | yes |
| large plasma proteins | no | yes |
| blood cells | no | no |
Explain the results for all three components shown in the table in terms of ultrafiltration in the kidney. Predict one resulting difference in the urine produced by a kidney with a filtration barrier modelled by membrane Q.
94 exam-style questions on Edexcel GCSE Biology 7.4 Blood glucose and the urinary system, covering 7.4.1 Insulin and blood glucose control, 7.4.2 Glucagon and blood glucose regulation, 7.4.3 Type 1 and type 2 diabetes, 7.4.4 Structure of the urinary system, 7.4.5 Structure and function of the nephron, 7.4.6 ADH and water regulation, 7.4.7 Treatments for kidney failure, and 7.4.8 Production of urea in the liver. Each one has a worked solution and a mark scheme showing where the marks go.