# Explain how the high specific heat capacity of water arises from hydrogen bonding between water molecules, and outline one consequence of this property for aquatic organisms.

> IB DP Biology Standard Level (2023 syllabus) — A1.1 Water · Explain · 4 marks

## Mark scheme (4 marks)

1. Water molecules are polar and form hydrogen bonds with each other.
2. A large amount of energy is required to increase the kinetic energy / temperature of water because energy must first be used to break / overcome hydrogen bonds before molecules can move faster.
3. This means water temperature changes slowly / resists rapid fluctuations in temperature.
4. One consequence for aquatic organisms: the relatively stable temperature of lakes / oceans / rivers prevents extreme thermal fluctuations, allowing aquatic organisms to maintain enzyme function / metabolic processes / physiological stability.

## Key terms

- [specific heat capacity](https://www.gradenine.co.uk/glossary/specific-heat-capacity)
- [hydrogen bond](https://www.gradenine.co.uk/glossary/hydrogen-bond)
- [aquatic organisms](https://www.gradenine.co.uk/glossary/aquatic-organisms)

## Related

- [Revision notes for IB DP Biology Standard Level (2023 syllabus)](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-how-the-high-specific-heat-6ba85075) · Published by Druglandscape Ltd.