A patient is diagnosed with type 2 diabetes. Unlike type 1 diabetes, the patient still produces insulin, but their body cells no longer respond to it effectively. As a result, their blood glucose concentration remains higher than normal after eating. Explain how, in a healthy person, blood glucose concentration would be returned to normal after eating a meal rich in carbohydrates.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Type 2 diabetes is a condition in which body cells become less sensitive to insulin. It is increasingly common and is linked to lifestyle factors such as poor diet and lack of exercise.
Model answer (5 marks)
1. After a carbohydrate‑rich meal, glucose is absorbed into the bloodstream, raising blood glucose concentration.
2. The pancreas senses this rise and secretes insulin into the blood.
3. Insulin binds to receptors on body cells and liver cells, signalling them to take up glucose from the blood.
4. Inside the liver, glucose is converted to glycogen and stored.
5. The decrease in blood glucose concentration brings it back to the normal level, demonstrating negative feedback and homeostasis.
2. The pancreas senses this rise and secretes insulin into the blood.
3. Insulin binds to receptors on body cells and liver cells, signalling them to take up glucose from the blood.
4. Inside the liver, glucose is converted to glycogen and stored.
5. The decrease in blood glucose concentration brings it back to the normal level, demonstrating negative feedback and homeostasis.
Examiner tips
- Use the exact terms: insulin, pancreas, glucose, glycogen, negative feedback. Show the sequence from rise to fall of glucose. Mention liver storage to cover all scheme points.
Common mistakes
- Confusing insulin with glucagon. Omitting the liver’s role in glycogen storage. Failing to state that the pancreas releases insulin in response to glucose.
Mark scheme (5 marks)
- Blood glucose concentration rises after eating carbohydrates / glucose is absorbed into the blood
- The pancreas detects the rise in blood glucose and releases / secretes insulin
- Insulin causes body cells / liver cells to take up / absorb glucose from the blood
- Glucose is converted to glycogen / stored as glycogen in the liver
- Blood glucose concentration returns to / is maintained at the normal level — this is an example of negative feedback / homeostasis
Key terms in this question
insulin · blood glucose concentration
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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