Which process primarily uses sunlight to create energy?

Photosynthesis is the process that primarily uses sunlight to create energy. During photosynthesis, plants, algae, and some bacteria convert light energy from the sun into chemical energy in the form of glucose. This process takes place mainly in the chloroplasts of plant cells, where chlorophyll absorbs sunlight and facilitates the conversion of carbon dioxide and water into glucose and oxygen.

The reaction can be summarized by the equation: 6CO2 + 6H2O + light energy → C6H12O6 + 6O2. This demonstrates that sunlight is a critical component in creating energy, as it drives the entire process.

In contrast, cellular respiration is the process by which cells break down glucose to produce energy, fermentation is an anaerobic process used to generate energy in the absence of oxygen, and glycolysis is the initial stage of cellular respiration that breaks down glucose into pyruvate, occurring in the cytoplasm and not relying on sunlight.