# Explain why cells need a continuous supply of ATP and describe two cellular processes that require ATP.

> AQA A-Level Biology (7402) — 3.1.6 ATP · Explain · 5 marks

> Cells are constantly carrying out processes that require energy. This energy is supplied by ATP, which is produced during respiration.

## Mark scheme (5 marks)

1. ATP cannot be stored in large amounts / cells have a limited store of ATP
2. ATP is continuously broken down / used up during cellular processes
3. ATP must therefore be continuously remade / resynthesised from ADP and phosphate during respiration
4. One correct cellular process named that requires ATP, e.g. muscle contraction / active transport / protein synthesis / cell division
5. A second correct cellular process named that requires ATP, different from the first

## Key terms

- [ATP](https://www.gradenine.co.uk/glossary/atp)

## 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)
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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-cells-need-a-continuous-5f97acfe) · Published by Druglandscape Ltd.