# Amino acids can join together to form peptides and proteins. Describe how amino acids are structured and explain how they join together to form a dipeptide, including the type of bond formed and the small molecule released.

> Eduqas A-Level Chemistry — 4.7 Amino acids, peptides and proteins · Describe and Explain · 5 marks

## Mark scheme (5 marks)

1. An amino acid contains an amino group (–NH₂)
2. An amino acid contains a carboxyl (carboxylic acid) group (–COOH)
3. The amino group of one amino acid reacts with the carboxyl group of another amino acid
4. A peptide bond is formed between the two amino acids
5. Water is released / produced during the reaction (condensation reaction)

## Key terms

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

## Related

- [Revision notes for Eduqas A-Level Chemistry](https://www.gradenine.co.uk/learn)
- [How to answer "Describe and Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/amino-acids-can-join-together-to-6149bfc2) · Published by Druglandscape Ltd.