# Explain the role of carrier proteins in active transport across a cell membrane.

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

## Mark scheme (4 marks)

1. Carrier proteins are embedded in the cell membrane
2. Molecules from the low-concentration side bind to the carrier protein
3. The carrier protein changes shape using energy from respiration
4. The molecule is moved through the membrane against the concentration gradient and released on the high-concentration side

## Key terms

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

## 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)
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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-the-role-of-carrier-proteins-3a073a56) · Published by Druglandscape Ltd.