# Explain the importance of phosphate ions and calcium ions in the human body.

> AQA A-Level Biology (7402) — 3.1.8 Inorganic Ions · Explain · 5 marks

## Mark scheme (5 marks)

1. Phosphate ions are a component of / needed to form DNA (and RNA) / nucleotides
2. Phosphate ions are a component of / needed to form ATP
3. Phosphate ions are a component of phospholipids (which form cell membranes)
4. Calcium ions are needed for / stimulate muscle contraction
5. Calcium ions are a component of / needed to form bones and teeth (as calcium phosphate / hydroxyapatite)

## Key terms

- [phosphate ions](https://www.gradenine.co.uk/glossary/phosphate-ions)
- [calcium ions](https://www.gradenine.co.uk/glossary/calcium-ions)

## Related

- [Revision notes for AQA A-Level Biology (7402)](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/explain-the-importance-of-phosphate-ions-2b983f62) · Published by Druglandscape Ltd.