# Explain the importance of calcium ions and sodium ions to the human body.

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

## Mark scheme (5 marks)

1. Calcium ions are needed for bone (and teeth) formation/structure
2. Calcium ions are needed for muscle contraction
3. Sodium ions are involved in the transmission of nerve impulses
4. Sodium ions are involved in the co-transport of glucose (and amino acids) into cells
5. Both ions are needed in low concentrations / as trace amounts and are examples of inorganic ions that have important functions despite being present in small quantities

## Key terms

- [calcium ions](https://www.gradenine.co.uk/glossary/calcium-ions)
- [sodium ions](https://www.gradenine.co.uk/glossary/sodium-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-calcium-ions-6c6aca27) · Published by Druglandscape Ltd.