Which item listed is NOT produced in the process of cellular respiration?

You originally start with glucose and metabolize it to get ATP. While glucose goes through glycolysis CO2 is produced. pyruvate is the final product in this step which then enters krebs cycle. CO2 is also a product of krebs cycle as well as GTP which is very similar to ATP. Co-factors NADH2 and FADH donate protons to Electron transport chain which in turn has water as a final product as well as ATP. I hope this helps!