Photosynthesis is the process of making your own food. Plants do this all the time. It's pretty much a trend for them. It all starts with chlorophyll. Chlorophyll traps sunlight which contains energy. This is light energy. Chloroplast also traps CO2 and O2. CO2 and O2 is carbon dioxide and oxygen. The plant gets H2O which is water from the roots. It travels through the xylem of and combines with the reactants in the leaves. Chloroplast combines all of the ingredients. This makes glucose. Glucose is the fancy word for sugar.