Cellular respiration according to equation
C₂H₂O₂ + 6O₂ ⇒ 6CO₂ + 6H₂O + ATP
This equation tells that glucose molecule is broken down in the presence of oxygen into carbon dioxide, water and energy. However, its mechanism is not so simple, it complete in three steps. In first step also known as glycolysis, glucose molecule is broken down into two pyruvates with expenditure of energy. In second step and third step ( Kreb cycle and ETC) most of the energy is released in the form of ATP
