Before we look at food chains we will go over the way green plants capture energy from the Sun to make food. This is the start of all the food chains we will look at.
Animals eat food to get their energy. But green plants don't. Instead they make their own food, glucose, in a process called photosynthesis. We say that plants can photosynthesise.
These are the things that plants need for photosynthesis:
These are the things that plants make by photosynthesis:
We can show photosynthesis in a word equation, where light energy is shown in brackets because it is not a substance:
carbon dioxide + water (+ light energy) → glucose + oxygen
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 oxygen produced is released into the air from the leaves. The glucose produced can be turned into other substances, such as starch, which is used as a store of energy. This energy can be released by respiration.
Photosynthesis takes place inside plant cells in small things called chloroplasts. Chloroplasts contain a green substance called chlorophyll. This absorbs the light energy needed to make photosynthesis happen. Plants can only photosynthesise in the light.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.