# A teenager is diagnosed with Type 1 diabetes. Their pancreas no longer produces insulin. Explain why the absence of insulin causes blood glucose levels to remain dangerously high after eating a meal, and describe how insulin injections help to restore normal blood glucose levels.

> OCR A-Level Biology B — Advancing Biology (H422) — 5.8 Hormonal communication · Explain · 5 marks

> Type 1 diabetes is an autoimmune condition in which the immune system destroys the insulin-producing cells of the pancreas. People with Type 1 diabetes must inject insulin before meals to manage their blood glucose levels.

## Mark scheme (5 marks)

1. After eating, glucose from digested food is absorbed into the blood, raising blood glucose levels
2. Normally insulin is released from the pancreas in response to high blood glucose
3. Insulin causes cells (liver / muscle cells) to take up glucose from the blood, lowering blood glucose concentration
4. Without insulin, cells cannot take up glucose, so blood glucose remains high / glucose is not converted to glycogen
5. Injecting insulin acts as a replacement hormone, allowing cells to take up glucose and blood glucose levels to return to normal

## Key terms

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

## Related

- [Revision notes for OCR A-Level Biology B — Advancing Biology (H422)](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-teenager-is-diagnosed-with-type-4f2a22d8) · Published by Druglandscape Ltd.