---
title: "Water and Hydrogen Bonding in Living Systems"
description: "Hydrogen bonds between water molecules give water its cohesion, its high heat capacity and its behaviour as a solvent. Every one of those properties traces back to the same charge separation across th"
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source: https://lightmysky.com/learn/science/water-and-hydrogen-bonding-in-living-systems-mt_79dzlo6fD5.md
retrieved: 2026-09-12
---

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# Water and Hydrogen Bonding in Living Systems

Hydrogen bonds between water molecules give water its cohesion, its high heat capacity and its behaviour as a solvent. Every one of those properties traces back to the same charge separation across the molecule.

Subject: Science · Area: Organisms & Life Processes · Ages 16 to 17
Page: https://lightmysky.com/learn/science/water-and-hydrogen-bonding-in-living-systems-mt_79dzlo6fD5

## Ready when they can

- Explains cohesion and surface tension from bonds between neighbouring molecules rather than from water being sticky.
- Links the high specific heat capacity to what hydrogen bonds do when heat is added.
- Predicts which solutes dissolve readily in water and says what about the molecule decides it.

## Lesson: Why water clings, cools slowly and dissolves salt

You saw water rush into red blood cells until they burst and into plant cells until walls held them firm. A water molecule is polar. Oxygen pulls shared electrons toward itself, leaving the oxygen end slightly negative and the hydrogen ends slightly positive. The hydrogen side of one molecule is drawn to the oxygen side of its neighbour, and that link is called a hydrogen bond. Each bond is weak, but together they act strong.

Those links explain everyday sights. Drops bead up, insects dent the surface without sinking, and water climbs thin plant stems as each molecule drags the next along. None of this happens because water is sticky like glue. It happens because neighbours keep holding hands, which is called cohesion.

Heating water means shaking that network apart, which soaks up a lot of energy. So water warms slowly and cools slowly, and that high heat capacity steadies the temperature inside living things.

Let polarity decide what dissolves. The charged ends of water surround ions and polar molecules and tug them apart, which is why salt vanishes into water. Molecules without charged regions get no such grip, so fats and oils bead up instead of mixing.

**Recap.** One polar molecule builds a network of bonds, and that network explains clinging, slow warming and dissolving.

## Practice

8 questions on this page, each with its working shown.

## Needs first

- [Osmosis in Plant and Animal Cells](https://lightmysky.com/learn/science/osmosis-in-plant-and-animal-cells-mt_XciCLO69xG)

## Opens up

- [Cohesion-Tension and Water Movement in the Xylem](https://lightmysky.com/learn/science/cohesion-tension-and-water-movement-in-the-xylem-mt_9_TORolYIl)
- [Protein Folding, Chaperones and What Misfolding Costs](https://lightmysky.com/learn/science/protein-folding-chaperones-and-what-misfolding-costs-mt_n9rlqjbaXK)
- [Condensation, Hydrolysis and the Polymers of Life](https://lightmysky.com/learn/science/condensation-hydrolysis-and-the-polymers-of-life-mt_v-M8zHd22C)