Answer:
Cellular respiration
Step-by-step explanation:
Oxygen is required by the cell in the Krebs cycle as the ultimate proton acceptor (creating water an end product during making out ATPs). During the conversion of pyruvate from glycolysis to Acetyl-CoA that enters the Krebs cycle, the pyruvate is decarboxylated (or oxidized) hence creating carbon IV oxide as a byproduct.