Glucose (sugar) + Oxygen → Carbon dioxide + Water + Energy (as ATP). Cellular respiration is what cells do to break up sugars into a form that the cell can use as energy. This happens in all forms of life. Cellular respiration takes in food and uses it to create ATP, a chemical which the cell uses for energy.Regular cellular respiration is aerobic (requires oxygen), but some simple organisms can only do anaerobic cellular respiration.ellular respiration takes in food and uses it to create ATP, a chemical which the cell uses for energy. Regular cellular respiration is aerobic (requires oxygen), but some simple organisms can only do anaerobic cellular respiration.