The primary gas for photosynthesis is carbon dioxide (CO2). During this process, plants, algae, and some bacteria convert carbon dioxide and water into glucose and oxygen, using sunlight's energy captured by chlorophyll. The overall equation for photosynthesis can be summarized as: 6CO2 + 6H2O + light energy → C6H12O6 + 6O2. This process is crucial for producing food and oxygen, sustaining most life on Earth. Photosynthesis not only supports plant growth but also plays a vital role in regulating atmospheric carbon dioxide levels, contributing to ecological balance and climate stability.