PHOTOSYNTHESIS

Animals eat to get food, but green plants make their own food. The process plants use is called photosynthesis. We say that plants can photosynthesise.

These are the things that plants need for photosynthesis:

• carbon dioxide
• water
• light

These are the things that plants make because of photosynthesis:

• glucose
• oxygen

We can show photosynthesis as this word equation:

carbon dioxide + water (+ light energy) = glucose + oxygen

(Light energy is shown in brackets because it is not a substance.)

This is the symbol equation for photosynthesis:

Where does this process take place in the plant?

Photosynthesis takes place in the chloroplasts in plant cells. Chloroplasts contain a green substance called chlorophyll. This absorbs the light energy needed to make photosynthesis happen. Plants can only photosynthesise in the light.

Palisade cells in leaves are tightly packed together and have lots of chloroplasts so can absorb a lot of light for photosynthesis.

Plants get carbon dioxide from the air through their leaves, and water from the ground through their roots.

Light energy comes from the sun.

The glucose produced can be turned into other substances, such as starch, which is used for storage. The oxygen produced is released into the air from the leaves.

Plants make food

Plants experiments - interactive site