During cellular respiration, four total ATP are produced when pyruvic acid is created. What else is produced as a result of this reaction?
A. water
B. heat
C. sugar
D. oxygen
The correct answer is B. heat.
During cellular respiration, pyruvic acid is produced through the process of glycolysis. This process generates a net gain of 2 ATP molecules. However, the production of the remaining ATP molecules (the other 2 ATP) occurs during the later stages of cellular respiration, such as the Krebs cycle and oxidative phosphorylation. In these stages, pyruvic acid is further broken down and energy is extracted in the form of ATP molecules. Apart from ATP, these reactions also produce heat as a byproduct. Oxygen is required for the later stages of cellular respiration, but it is not produced during the creation of pyruvic acid.