Green plants trap light energy and synthesize carbohydrate molecules via the reactions of photosynthesis.
Plant cells use the raw materials carbon dioxide and water, and release oxygen as a waste product.
Virtually all familiar life forms depend on photosynthesis for energy and organic carbon. In plants, photosynthetic reactions take place in green cellular organelles called chloroplasts. One set of reactions traps light energy and releases oxygen from water. Another set removes carbon dioxide from the air and combines it with hydrogen to produce biologically useful carbohydrates. This reaction is reciprocal to aerobic respiration in plants and other organisms.