# Explain how urea is produced in the liver and subsequently removed from the body by the kidneys.

> Pearson Edexcel International GCSE Biology (4BI1) — 2.13 Excretion: humans · Explain · 4 marks

## Mark scheme (4 marks)

1. Excess amino acids cannot be stored and are broken down (deaminated) in the liver
2. The nitrogen-containing part of the amino acid is converted to urea (in the liver)
3. Urea passes from the liver into the blood and is transported to the kidneys
4. The kidneys filter urea out of the blood and it is excreted in urine

## Key terms

- [urea](https://www.gradenine.co.uk/glossary/urea)
- [liver](https://www.gradenine.co.uk/glossary/liver)
- [kidneys](https://www.gradenine.co.uk/glossary/kidneys)

## Related

- [Revision notes for Pearson Edexcel International GCSE Biology (4BI1)](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-urea-is-produced-in-d1156d78) · Published by Druglandscape Ltd.