# A patient with type 1 diabetes cannot produce insulin. Explain how insulin normally controls blood glucose concentration in a healthy person, and why maintaining a constant blood glucose concentration is important for the body's cells.

> Pearson Edexcel A-Level Biology A (9BI0) — 4.6 Homeostasis · Explain · 5 marks

> Blood glucose concentration in a healthy person is kept within a narrow range. In type 1 diabetes, the cells of the pancreas that produce insulin are destroyed by the immune system.

## Mark scheme (5 marks)

1. After a meal, blood glucose concentration rises / increases
2. The pancreas detects the rise and releases / secretes insulin into the blood
3. Insulin causes the liver (and muscle cells) to convert excess glucose into glycogen for storage
4. This lowers / returns blood glucose concentration to the normal level (negative feedback)
5. Cells need a constant supply of glucose for respiration to release energy; too much or too little glucose would disrupt cell processes / damage cells

## Key terms

- [insulin](https://www.gradenine.co.uk/glossary/insulin)
- [blood glucose concentration](https://www.gradenine.co.uk/glossary/blood-glucose-concentration)

## Related

- [Revision notes for Pearson Edexcel A-Level Biology A (9BI0)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-patient-with-type-1-diabetes-bc2330dc) · Published by Druglandscape Ltd.