# Describe the structure of DNA, including the type of monomers it is made from, and explain how the structure of a polypeptide differs from the structure of DNA.

> AQA A-Level Chemistry (7405) — 3.3.13 Amino acids, proteins and DNA (A-Level only) · Describe · 5 marks

## Mark scheme (5 marks)

1. DNA is made from nucleotide monomers
2. DNA is made from four different nucleotides
3. DNA consists of two polymer chains in the form of a double helix
4. A polypeptide is made from amino acid monomers (not nucleotides)
5. A polypeptide is a single polymer chain, whereas DNA has two polymer chains

## Key terms

- [DNA](https://www.gradenine.co.uk/glossary/dna)
- [polypeptide](https://www.gradenine.co.uk/glossary/polypeptide)

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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-the-structure-of-dna-including-7fa20413) · Published by Druglandscape Ltd.