Photosynthesis. Photosynthesis is a process used by plants in which energy from sunlight is used to convert carbon dioxide and water into molecules needed for growth. These molecules include sugars, enzymes and chlorophyll.Light energy is absorbed by the green chemical chlorophyll.lucose from photosynthesis. Glucose is made up of carbon, hydrogen and oxygen atoms. Glucose made by the process of photosynthesis may be used in three ways: 1  It can be converted into chemicals required for growth of plant cells such as cellulose.