CourseCourseConceptConceptDocumentDocument

Edexcel IGCSE Biology 2 77b Selective Reabsorption of Glucose Questions

Trace glucose from the filtrate into blood and connect its recovery in the proximal convoluted tubule with active transport and ATP.

Syllabus
First assessment 2019
Course
Biology 4BI1

Exam points

  • Explain why glucose is selectively reabsorbed from filtrate into blood in the proximal convoluted tubule.
  • Explain how active transport moves glucose into blood using ATP and uptake against its concentration gradient.
  • Interpret glucose concentration changes between nephron regions as glucose is reabsorbed in the proximal tubule.

Edexcel IGCSE Biology 2 77b Selective Reabsorption of Glucose Questions question 1

[Maximum number: 2]

Read the passage below. Use the information in the passage and your own knowledge to answer the questions that follow.

Treating Kidney Disease

Chronic kidney disease affects approximately 12% of the world's population and many people are unable to obtain treatment. One method of treating chronic kidney disease is by dialysis. The diagram shows how kidney dialysis is done.

Figure for Question Edexcel IGCSE Biology 2 77b Selective Reabsorption of Glucose Questions question 1 — Edexcel IGCSE Biology

During dialysis, blood is taken from an artery in the arm and is pumped through a dialyser. In the dialyser, the blood passes through a long, coiled dialysis tube made of a thin partially permeable membrane. The tube is surrounded by dialysis fluid. The dialysis fluid contains glucose and ions at concentrations normally found in blood plasma, but does not contain urea. The urea passes from the blood into the dialysis fluid. The temperature in the dialyser is kept at 40∘C40^{\circ} \mathrm{C}. After passing through the dialyser, the blood is returned to a vein in the arm. Kidney dialysis can take up to three hours and must be done three times a week.

Scientists have now designed a new bioartificial kidney. This artificial kidney is a combination of engineering and living cells. This artificial kidney has a haemofilter made from artificial membranes that filter the blood. The substances filtered out of the blood then pass through a device called a bioreactor. This bioreactor absorbs useful substances back into the blood. The bioreactor is made of living nephron cells that are grown from stem cells. These cells are separated from the patient's blood by a silicon membrane to prevent the immune system rejecting them. Bioartificial kidneys are the same size as a human kidney and will be fitted inside the body to replace a kidney. The bioartificial kidney can react to changes in the body in the same way as a normal kidney.

The cells in the bioreactor absorb glucose from the filtrate in a way that is similar to the cells in a nephron (Lines 14 to 17).

Describe how the nephron absorbs glucose back into the blood from the filtrate.

All question bank results loaded