Answer:
The bonds between the atoms in the input molecules are broken and new bonds are formed to produce the output molecules.
Step-by-step explanation:
Cellular respiration is a metabolic (catabolic) process carried out by the cells of all living organisms because it is the way usable energy in form of ATP is obtained. All organisms feed in order to acquire energy, the energy is stored in the chemical bonds of the digested food (glucose).
The process of cellular respiration then breaks down the food molecule in order to release the stored energy and convert it to ATP, which is the energy currency usable by the cell. The general equation of cellular respiration is:
C6H12O6 + 6O2 -----> 6CO2 + 6H2O
Since the energy is initially stored in the bonds of the input molecule (glucose), the bonds needs to be broken in order to assess the energy. Hence, cellular respiration breaks the bonds in the input molecules and rearranges the atoms by a new bond to form the output molecules (CO2 and H2O).