# Describe the roles of carbohydrates, fats, and fibre in the human body, and explain why a person who eats too little fibre may experience constipation.

> Cambridge International IGCSE Biology (0610) — 7.1 Diet · Describe · 4 marks

## Mark scheme (4 marks)

1. Carbohydrates are used as a source of energy (in respiration in cells).
2. Fats have a role in insulation / energy storage / protection of delicate organs / structure (any one acceptable).
3. Fibre is not digested and adds bulk to the faeces / helps food move through the intestines.
4. Without sufficient fibre, faeces become harder / less bulk means the intestine cannot move food along efficiently, resulting in constipation.

## Key terms

- [carbohydrates](https://www.gradenine.co.uk/glossary/carbohydrates)
- [fats](https://www.gradenine.co.uk/glossary/fats)
- [fibre](https://www.gradenine.co.uk/glossary/fibre)
- [constipation](https://www.gradenine.co.uk/glossary/constipation)

## Related

- [Revision notes for Cambridge International IGCSE Biology (0610)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" 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/describe-the-roles-of-carbohydrates-fats-faa4dffb) · Published by Druglandscape Ltd.