# Explain why two different proteins can both be made from the same twenty amino acids, yet have completely different shapes and functions in the body.

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

## Mark scheme (5 marks)

1. The sequence (order) of amino acids in a protein can vary
2. Amino acids are joined by peptide bonds to form a chain (polypeptide)
3. The chain folds into a specific three-dimensional shape
4. Different sequences produce different shapes/structures
5. The specific shape of a protein determines its function

## Key terms

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

## Related

- [Revision notes for Eduqas A-Level Chemistry](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-two-different-proteins-can-f6337c3a) · Published by Druglandscape Ltd.