A person eats a large meal high in carbohydrates. Explain how the body responds to restore normal blood glucose concentration after this meal.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
After eating a meal rich in carbohydrates, blood glucose concentration rises above the normal level. The body detects this change and responds to bring blood glucose concentration back to normal.
Model answer (5 marks)
The pancreas senses the increased glucose level and secretes insulin into the blood.
Insulin acts on liver and muscle cells, stimulating the conversion of glucose to glycogen and uptake of glucose from the bloodstream.
As glucose is removed from the blood, the concentration falls back to the normal range.
This reduction in glucose is a corrective response that opposes the initial rise.
Thus the system operates as a negative‑feedback loop, restoring homeostasis.
Insulin acts on liver and muscle cells, stimulating the conversion of glucose to glycogen and uptake of glucose from the bloodstream.
As glucose is removed from the blood, the concentration falls back to the normal range.
This reduction in glucose is a corrective response that opposes the initial rise.
Thus the system operates as a negative‑feedback loop, restoring homeostasis.
Examiner tips
- Use the word ‘secretes’ for insulin release. Show the sequence: detection → insulin release → action on liver/muscle → glucose falls. Mention negative feedback explicitly to earn the final point.
Common mistakes
- Confusing glucagon with insulin. Failing to state that insulin acts on liver and muscle. Omitting the negative‑feedback description.
Mark scheme (5 marks)
- The pancreas detects the rise in blood glucose concentration
- The pancreas releases/secretes insulin (into the blood)
- Insulin causes the liver (and muscle cells) to convert glucose to glycogen / remove glucose from the blood
- Blood glucose concentration falls / returns to the normal level
- This is an example of negative feedback / the corrective response reduces the original change
Key terms in this question
Related
- All Pearson Edexcel A-Level Biology A (9BI0) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
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