# Describe how yeast is used in bread-making and explain why the bread rises during this process.

> Pearson Edexcel International GCSE Biology (4BI1) — 5.1 Food production · Describe · 4 marks

## Mark scheme (4 marks)

1. Yeast carries out anaerobic respiration (in the dough)
2. Carbon dioxide is produced (as a product of anaerobic respiration)
3. The carbon dioxide causes the bread to rise (by forming bubbles / expanding the dough)
4. Alcohol is also produced but evaporates (during baking)

## Key terms

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

## Related

- [Revision notes for Pearson Edexcel International GCSE Biology (4BI1)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-how-yeast-is-used-in-fdb45630) · Published by Druglandscape Ltd.