Animals need to eat food to get their energy. But green plants and algae do not. Instead they make their own food in a process called photosynthesis. Almost all life on Earth depends upon this process. Photosynthesis is also important in maintaining the levels of oxygen and carbon dioxide in the atmosphere.
These are the things that plants need for photosynthesis:
These are the things that plants make by photosynthesis:
Here is the word equation for photosynthesis:
Photosynthesis takes place inside plant cells in small objects called chloroplasts. Chloroplasts contain a green substance called chlorophyll. This absorbs the light energy needed to make photosynthesis happen. Plants and algae can only carry out photosynthesis in the light.
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 and plant oils, which are used as an energy store. This energy can be released by respiration.