The gas produced as a by-product of photosynthesis is oxygen (O2). During this natural process, plants, algae, and certain bacteria use sunlight to convert carbon dioxide and water into glucose and oxygen. Photosynthesis primarily takes place in the chloroplasts of plant cells, where chlorophyll captures sunlight. The overall equation for photosynthesis can be simplified to: 6CO2 + 6H2O + light energy → C6H12O6 + 6O2. The oxygen released during photosynthesis is essential for life on Earth, as it is used by animals and humans for respiration, while the glucose produced serves as an energy source for the plants themselves and other organisms in the ecosystem.