|Photosynthesis in Plants|
Unlike animals, plants do not obtain their food by eating other things. Using physical and chemical reactions involving light, a plant actually creates its own food. Thus, photosynthesis is the way that a plant makes food for itself.
Chlorophyll is the green part of the leaves; it captures energy from the sun, and this powers the building of food from very simple ingredients - carbon dioxide and water. Chlorophyll uses red and blue light, but does not use green light. This causes the green light to be reflected, giving leaves their green color.
Photosynthesis can be described by a simple chemical equation. Six molecules of water plus six molecules of carbon dioxide produce one molecule of sugar plus six molecules of oxygen. This can be broken down further and looks like this:
6H2O + 6CO2 -- > C6H12O6 + 6O2
So in simple terms, plants breathe in carbon dioxide and use it to produce food for themselves; when they are done, they breathe out oxygen. We should thank plants everyday because we depend on oxygen for breathing! The oxygen actually comes from the photolysis (breakdown involving light) of water, not from the carbon dioxide. Photosynthesis also helps to supply food, fibers, medicines, etc. so oxygen is not the only way that humans and animals benefit from photosynthesis!