# Explain why active transport, rather than diffusion, is needed for the uptake of glucose in the small intestine.

> Cambridge International IGCSE Biology (0610) — 3.3 Active transport · Explain · 4 marks

> After a meal is digested, glucose must be absorbed from the small intestine into the blood. Even when the concentration of glucose inside the intestinal cells is already higher than in the intestine, glucose continues to be absorbed.

## Mark scheme (4 marks)

1. Glucose moves against its concentration gradient (from low to high concentration)
2. Diffusion cannot move substances against a concentration gradient / diffusion only moves substances down a concentration gradient
3. Active transport uses carrier proteins to move glucose across the cell membrane
4. Active transport requires energy from respiration

## Key terms

- [active transport](https://www.gradenine.co.uk/glossary/active-transport)
- [diffusion](https://www.gradenine.co.uk/glossary/diffusion)

## Related

- [Revision notes for Cambridge International IGCSE Biology (0610)](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/explain-why-active-transport-rather-than-405cac8b) · Published by Druglandscape Ltd.