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How do plants make food?

A diagram showing how photosynthesis worksA diagram showing how photosynthesis worksA plant uses its green leaves to receive sunlight. The leaves also take in carbon dioxide from the air, while water and vital minerals and nutrients are soaked up from the soil through the roots. The sunlight energy joins the water and carbon dioxide together to make a sugar called glucose. As this happens, waste oxygen and water vapour pass from the leaves into the air. Living things, including ourselves, need oxygen to survive. Plants help to top up its level in the air.



 A close-up view of a leaf, showing its veins A close-up view of a leaf, showing its veins

Leaves

Photosynthesis happens in a plant’s leaves. These contain tiny tubes, called veins. Some bring water from the roots up into the leaf. Others deliver the sap—water containing the dissolved sugars produced by photosynthesis—to the rest of the plant.




A photo taken through a microscope of leaf cellsA photo taken through a microscope of leaf cells

Inside a leaf

A plant’s leaves are broad and flat so that as much light as possible can fall on them. Inside the cells in the leaf’s upper surface are a large number of tiny blobs. These are called chloroplasts. They contain chlorophyll, a green substance that absorbs the energy in sunlight. 

The sequence of chemical changes in photosynthesis takes place in a millionth of a second.

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