# Explain how facilitated diffusion differs from active transport in terms of energy use and direction of movement across the plasma membrane.

> IB DP Biology Standard Level (2023 syllabus) — B2.1 Membranes and membrane transport · Explain · 4 marks

## Mark scheme (4 marks)

1. Facilitated diffusion does not require ATP / metabolic energy, whereas active transport does require ATP / metabolic energy.
2. Facilitated diffusion moves substances down / along their concentration gradient (from high to low concentration).
3. Active transport moves substances against / up their concentration gradient (from low to high concentration).
4. Both processes use (integral / transmembrane) proteins — facilitated diffusion uses channel or carrier proteins, and active transport uses carrier / pump proteins — but only active transport involves a conformational change driven by ATP hydrolysis.

## Key terms

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

## Related

- [Revision notes for IB DP Biology Standard Level (2023 syllabus)](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-how-facilitated-diffusion-differs-from-1ca65eca) · Published by Druglandscape Ltd.