The process in green plants and certain other organisms by which carbohydrates are synthesized from carbon dioxide and water using light as an energy source. Most forms of photosynthesis release oxygen as a byproduct.
详情请见对应中文词条：光合作用
Added Part ： The comlex proess inside a leaf takes energy from the sun and uses it to convert water and carbon dioxide into sugars.During the process- photosynthesis --plants convert light energy into chemical energy.
All leaves carry out photosynthesis in basically the same way. First,the pores on the leaf's outer skin open up and take in molecules of carbon dioxide.Water abosorbed by the toots is trasported upward through the plant,and it enters the leaf through its system.Carbon dioxide and the water are present, photosynthesis can begin.
The chemical reactions of photosynthesis take place in two stages: the light -dependent reactions and the light-independent reactions.When sun light shines on aleaf during the light-dependent stage,its energy is abosorbed by molecules of chlorophyll,which you know is the pigment giving a leaf its green color。 The light energy abosorbed by the chorophyll is used to split the hydrogen and oxygenin the water.Then, during the light-independent reactions,hydrogen from the water combines with carbon dioxide,and forms carbonhydrates,including the sugar glucose,bu also other molecules that are rich in food energy for the plant.In the process,excess oxygen is released to the outside air through the leaf's pores.
Finally,the plant transports the products of photosynthesis.Microscopic veins in the leaf carry the food out through the stem and into the cells of the plant.This process continues all throughout the growing season,that is ,as long as the leaves remain green.