Energy in Food – Photosynthesis
The Process of Photosynthesis
Plants need three essential conditions for photosynthesis – carbon dioxide, water and light! Plants undergo photosynthesis in order to make food, giving out oxygen in the process which all animals and human beings need to breathe in to stay alive.
Light is Needed for Photosynthesis
Some chemical indicators change in colour according to the amount of gases such as carbon dioxide in the surroundings. In the experiment below, an indicator solution is yellow in the presence of a high amount of carbon dioxide, green in a low amount of carbon dioxide and blue when no carbon dioxide is present.