9. Photosynthesis Photosynthesis is the way a plant makes food for itself. Chlorophyll in the "green" part of the leaves captures energy from the sun and this powers the building of food from very simple ingredients - carbon dioxide and water. Oxygen is released as a by-product of photosynthesis. 6 Waters + 6 Carbon Dioxides + Sunlight energy------> Glucose+ 6 Oxygens