# Ethanol can be produced by fermentation of sugar solutions using yeast. Ethanol can also be produced by a different method. Describe the process of fermentation and explain why ethanol produced by fermentation is considered a renewable fuel.

> AQA A-Level Chemistry (7405) — 3.3.15 NMR spectroscopy (A-Level only) · Describe and Explain · 5 marks

## Mark scheme (5 marks)

1. Fermentation involves the breakdown of sugar (glucose) anaerobically
2. Yeast is used as the organism/catalyst in fermentation
3. Ethanol (and carbon dioxide) are produced during fermentation
4. The sugar/glucose used in fermentation comes from plants, which are a renewable/living source
5. When ethanol is burned, the CO2 released was previously absorbed by the plants during photosynthesis, so it is (approximately) carbon neutral / does not add new carbon dioxide to the atmosphere

## Key terms

- [fermentation](https://www.gradenine.co.uk/glossary/fermentation)
- [ethanol](https://www.gradenine.co.uk/glossary/ethanol)
- [yeast](https://www.gradenine.co.uk/glossary/yeast)
- [renewable](https://www.gradenine.co.uk/glossary/renewable)

## Related

- [Revision notes for AQA A-Level Chemistry (7405)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe and 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/ethanol-can-be-produced-by-fermentation-c2689612) · Published by Druglandscape Ltd.