Photosynthesis vs. Cellular respiration
Photosynthesis and cellular respiration are complementary processes by which living things obtain needed substances. They both consume and create the same substances (water, glucose, oxygen, and carbon dioxide) but in different ways. Through these processes, plants obtain the carbon dioxide they need and living organisms obtain the oxygen they need. They are also necessary to the energy exchange that living things need to survive.
Photosynthesis is the process by which green plants create their own food by turning light energy into chemical energy. Chlorophyll in the leaves transform carbon dioxide, water, and minerals into oxygen and glucose. Photosynthesis takes place in the chloroplasts of cells. This process is what gives energy to all living organisms either directly or indirectly. Without it, life on Earth would cease to exist.
Cellular respiration, on the other hand, is the process by which living things convert oxygen and glucose to carbon dioxide and water, thereby yielding energy. It does not require the presence of sunlight and is always occurring in living organisms. Cellular respiration takes place in the mitochondria of cells.
While photosynthesis requires energy and produces food, cellular respiration breaks down food and releases energy. Plants perform both photosynthesis and respiration, while animals can only perform respiration.