Explain how the hormone insulin helps to restore blood glucose concentration back to its optimum level after a meal high in carbohydrates. In your answer, refer to the role of the pancreas and the liver.

Eduqas A-Level Biology — 4.2 Inheritance · Explain · 5 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

After eating a large meal containing bread, pasta and sugary drinks, the blood glucose concentration of a person rises well above the optimum level.

Model answer (5 marks)

The pancreas senses the rise in blood glucose and secretes insulin into the bloodstream.
Insulin circulates to target cells, such as muscle and adipose tissue.
It binds to receptors on these cells, stimulating glucose transporters and increasing glucose uptake from the blood.
In the liver, insulin promotes the conversion of glucose into glycogen for storage.
This negative‑feedback loop lowers blood glucose back to the optimum level.

Examiner tips

  • Use the word ‘secretes’ for the pancreas, ‘circulates’ for insulin, and ‘stimulates’ for glucose uptake.
  • Show the sequence: detection → secretion → transport → action on cells and liver → feedback.
  • Mention negative feedback explicitly to gain the full mark.

Common mistakes

  • Confusing insulin with glucagon or omitting the pancreas’s role.
  • Failing to state that insulin increases glucose transport into cells.
  • Not identifying the negative‑feedback nature of the process.

Mark scheme (5 marks)

  1. The pancreas detects the rise in blood glucose concentration and releases / secretes insulin (into the blood).
  2. Insulin travels in the blood(stream) to target organs / cells.
  3. Insulin increases the uptake of glucose into cells (from the blood).
  4. Insulin causes the liver to convert glucose into glycogen (for storage).
  5. This is an example of negative feedback — the corrective mechanism returns blood glucose concentration back to the optimum / normal level.

Key terms in this question

insulin · pancreas · blood glucose concentration

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