Photosynthesis and cellular respiration are interconnected processes that sustain life. Photosynthesis converts sunlight, water, and carbon dioxide into glucose and oxygen, providing the energy source for cellular respiration. Cellular respiration utilizes glucose and oxygen to produce ATP, the energy currency of cells. This symbiotic relationship ensures a continuous energy cycle, with photosynthesis supplying the fuel for cellular respiration and cellular respiration releasing oxygen for photosynthesis.