The answer is: Water.
Chemical reaction of cellular respiration (convert biochemical energy):
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O.
glucose + oxygen → carbon dioxide + water + energy .
This reaction is exothermic (energy is released).
Carbon dioxide and water are released during cellular respiration.
In cellular respiration where organic matter is transformed into carbon dioxide and energy is released for production of ATP.
Glucose and oxygen are reactants and carbon dioxide, water and energy are products of this chemical reaction; cellular respiration creates an energy molecule (ATP) when glucose is broken down.