What is the correct general equation for cellular respiration?

The general equation for aerobic cellular respiration, the process by which cells convert glucose and oxygen into ATP, is:

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP

This equation shows that one molecule of glucose (C₆H₁₂O₆) reacts with six molecules of oxygen (O₂) to produce six molecules of carbon dioxide (CO₂), six molecules of water (H₂O), and energy in the form of ATP (adenosine triphosphate). ATP is the primary energy currency of the cell; it stores and transfers energy for nearly all cellular processes. When ATP is broken down into ADP (adenosine diphosphate) and inorganic phosphate (Pi), energy is released to power activities such as muscle contraction, active transport across membranes, protein synthesis, and cell division.

Cellular respiration occurs in several stages: glycolysis (in the cytoplasm), the link reaction and Krebs cycle (in the mitochondrial matrix), and the electron transport chain (across the inner mitochondrial membrane). Oxygen is essential in the final stage, acting as the terminal electron acceptor in the electron transport chain, which enables the production of most of the ATP during respiration. In total, aerobic respiration can yield up to 36 to 38 ATP molecules per glucose molecule, making it far more efficient than anaerobic pathways, which produce only 2 ATP per glucose molecule. This efficiency makes aerobic respiration vital for energy-demanding organisms like animals, plants, and many fungi.