Answer:
Oxygen
Step-by-step explanation:
Cellular respiration is the process whereby living organisms synthesize energy in form of ATP. However, it can either be aerobic or anaerobic depending on whether it occurs with or without oxygen. Aerobic respiration occurs in the presence of oxygen.
The aerobic cellular respiration is further divided into glycolysis, Krebs cycle and oxidative phosphorylation. The oxidative reactions used by aerobic bacteria to generate ATP use OXYGEN as a terminal or final electron acceptor.