How does the body produce carbon dioxide?

Well carbon dioxide is produced when the body needs to make energy. It happens at the cellular level, in the mitochondria of the cell. This organelle takes marcomolecules, anything from lipids, sugars, and other substances, and breaks them down to form water and carbon dioxide. That is why the body creates urine and Excels carbon dioxide. This whole process cannot occur without oxygen and that is why we need it to survive. The reason why we need oxygen is because it is the final electron acceptor in the electron transport chain.