The cell wall is a tough outer case of cellulose that helps support the plant and gives the cell a rigid structure. In addition, the cell wall provides protection and form to the cell and its contents.
What is the function of cell walls?
Cell walls provide strength and structure. The structure protects everything inside the cell – the cell membrane, nucleus, nucleolus, mitochondria, chloroplast, cytoplasm, and large vacuole – and its strength allows plants to grow tall.
Cell walls also provide structure and strength to the living things they make up.
The material of the cell wall allows very small molecules to pass through into the cell to spread water and carbon dioxide around the plant.
What are cell walls made of?
Cell walls are made of long cellulose, pectin, and hemicellulose molecules. Cellulose is made of specialized sugar, but it isn’t used to give living thing energy. Instead, this sugar is a ‘structural carbohydrate’ which doesn’t dissolve in water, meaning that it can form long chains which give plants support as they grow.
Some cell walls are divided into primary and secondary cell walls. The primary cell wall is more permeable, allowing things that are needed to pass into the cell. But the secondary cell wall makes the cell stiffer and stronger by adding an extra layer of cellulose.
Did You Know…? Sometimes not even eating a plant can destroy the cellulose to make energy. This is because certain bacteria in the stomachs of herbivores allow them to digest the plants they eat.
Do all cells have cell walls?
No, not every type of cell has a cell wall. The cell wall provides strength and structure that supports plants as they grow larger, allowing them to keep their weight. Animal cells don’t need to do this as animals have skeletons and cartilage, which do this and provide the form.
These types of cells have cell walls:
- plant cells;
- bacterial cells;
- fungal cells;
- algae cells.
Two facts about cell walls
- Have you ever wondered why plants bounce about in the wind and can return to their original shape? The cell walls in plant cells have elastic properties, which allow smaller plants and leaves to bounce back into shape.
- A cell wall is constructed of fibers that form in different directions to strengthen the wall.