# Describe the roles of proteins and lipids as biological molecules in living organisms.

> Pearson Edexcel International GCSE Biology (4BI1) — 2.3 Biological molecules · Describe · 4 marks

## Mark scheme (4 marks)

1. Proteins are large molecules made up of amino acids
2. Proteins have a structural or functional role, e.g. enzymes / antibodies / muscle / haemoglobin
3. Lipids are made from fatty acids and glycerol
4. Lipids serve as an energy store / provide insulation / make up cell membranes

## Key terms

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

## 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-the-roles-of-proteins-and-5af4ebeb) · Published by Druglandscape Ltd.