Answer:
The breakdown of carbohydrates in the cell during cellular respiration does not change the matter or energy in the molecule. Actually, the matter in the energy molecule, which is the number of atoms and molecule, remains the same and are only transferred to make other molecules (remember that in a chemical reaction, the number of atoms on the reactants side must balance with those of the products). The energy in the bonds of the molecule, as they are broken down by metabolic enzymes, are what is transferred to ATPs. This process is not efficient as most energy is lost as heat. The energy in the ATPs is used in catabolic process like the formation of carbohydrates in the Calvin cycle of plants. Catabolic processes reduce entropy - & increase Gibbs free energy - hence require energy.
Ultimately, no energy or matter is destroyed or made, it is only transferred, hence observing the first law of thermodynamics.
Energy in the body is stored through glycogenesis where glycogen is formed from excess glucose and stored in tissues. When energy is required, this glycogen is broken down back to glucose through glycogenolysis and it can be used in cellular respiration.
