Cell Wall
The cell wall is the rigid layer found outside the cell membrane in plant cells, and it is made of cellulose — one of the carbohydrates built from glucose during photosynthesis 1. Bacterial cells also have a cell wall; animal cells do not.
| Property | Consequence |
|---|---|
| Rigid and made of cellulose | Gives the cell a fixed shape and mechanical strength |
| Fully permeable | Does not control entry and exit — that is the cell membrane’s job |
| Resists internal pressure | Balances the outward push of water in the vacuole |
| Present in plants, absent in animals | Plant cells have regular shapes; animal cells stay irregular |
Turgor and Support
Plants are supported by the pressure of water inside their cells pressing outwards on the cell wall 1. A cell that has taken in water by osmosis is turgid and presses back on its wall, so soft plant tissues such as leaves stand upright. When cells lose water they become flaccid, and the plant wilts — which is why support in plants depends on water as much as on the wall itself.
Related
- Cell - Structural unit surrounded by the wall.
- Cell Membrane - Partially permeable layer inside the wall.
- Water Potential - The gradient producing the turgor pressure.
- Osmosis - Water movement whose pressure the wall resists.
- Small Vacuole - Water stores whose pressure the wall resists.
- Chloroplast - Source of the cellulose used to build the wall.
- Biology - Cambridge IGCSE life-science area.
Footnotes
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Cambridge IGCSE Biology 0610 syllabus for examination in 2026, 2027 and 2028 - Cell wall in plant and bacterial cells (2.1.1-2.1.4), cellulose from glucose (6.1.5), turgor pressure and support (3.2). ↩ ↩2