Photosynthesis is one of the most important biological processes on Earth. It's how plants, algae, and some bacteria convert sunlight into chemical energy. The process requires three main inputs: carbon dioxide from the air, water from the soil, and sunlight as the energy source. The green pigment chlorophyll captures the light energy. The overall equation shows six molecules of carbon dioxide plus six molecules of water, combined with light energy, producing one molecule of glucose and six molecules of oxygen.