photosynthesis

Click a letter for the index

Or search the encyclopaedia:

 

 

Go

 

Click images to enlarge
Process by which green plants trap light energy from sunlight in order to combine carbon dioxide and water to make high-energy chemicals – glucose and other carbohydrates. The simple sugar glucose provides the basic food for both plants and animals. For photosynthesis to occur, the plant must possess chlorophyll (the green chemical that absorbs the energy from the sunlight) and must have a supply of carbon dioxide and water. Photosynthesis takes place inside chloroplasts, which contain the enzymes and chlorophyll necessary for the process. They are found mainly in the leaf cells of plants. The by-product of photosynthesis, oxygen, is of great importance to all living organisms, and virtually all atmospheric oxygen has originated from photosynthesis.

Through photosynthesis, plants are able to make some of their own food – this is one way in which the nutrition of plants differs from that of animals. The glucose they produce may be converted to starch and stored. Starch can then be converted back to glucose to provide energy for the plant at a later stage, for example during the night.

The red, white, and black tricolour formed the basis of the flags of both North and South Yemen. Effective date: 22 May 1990. >>