What is the equation for cellular respiration?

• A. C6H12O6 + 6O2 => 6CO2 + 6H2O + Energy
• B. C6H12O6 => 2 CO2 + 2 H2O
• C. C6H12O6 + 6O2 => 6CO2 + 6H2O + ADP
• D. ATP + Oxygen => Glucose

Answer: (A)

Cellular respiration releases the energy stored in glucose by using oxygen to form carbon dioxide and water, with the energy captured in ATP. The best representation of this process is glucose plus six oxygen molecules yielding six carbon dioxide, six water molecules, and energy stored as ATP.

That option is correct because it shows both the reactants (glucose and oxygen) and the proper end products (carbon dioxide and water) with the energy captured as ATP. The other formulations don’t fit: one omits oxygen and ATP, another places ADP as a product instead of ATP, and another shows ATP and oxygen converting back to glucose, which is the reverse process of respiration (photosynthesis).