# Amino acids can join together to form peptides and proteins. Explain how amino acids are linked together to form a dipeptide, and describe how the structure of a protein is related to its function.

> WJEC A-Level Chemistry (Wales) — 4.7 Amino acids, peptides and proteins · Explain · 5 marks

## Mark scheme (5 marks)

1. Two amino acids join together to form a dipeptide
2. A peptide bond is formed between the two amino acids
3. Water is released / eliminated during the formation of the peptide bond (condensation reaction)
4. Many amino acids join together in a chain to form a polypeptide / protein
5. The sequence / order of amino acids determines the shape of the protein, and the specific shape allows the protein to carry out its function

## Key terms

- [amino acid](https://www.gradenine.co.uk/glossary/amino-acid)
- [dipeptide](https://www.gradenine.co.uk/glossary/dipeptide)
- [protein](https://www.gradenine.co.uk/glossary/protein)

## Related

- [Revision notes for WJEC A-Level Chemistry (Wales)](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/amino-acids-can-join-together-to-13f5e14a) · Published by Druglandscape Ltd.