For cellular respiration, glucose (sugar) plus oxygen equals carbon dioxide plus water plus energy (as ATP). This reaction has a balanced chemical equation: C6H1206 + 6O2 = 6CO2 + 6H2O + energy (ATP). But cellular respiration or aerobic respiration happens in steps, such as glycolysis and Kreb’s cycle.
The energy that is made by this reaction is temporarily stored in molecules of adenosine triphosphate. Cells have ATP in their cytoplasm.
The chemical equation for how cells breathe is the opposite of the equation for how plants make food, which is called photosynthesis. Through photosynthesis, plants use carbon dioxide and water as reactants to make glucose and oxygen.