Does cellular respiration require oxygen?

Does cellular respiration require oxygen?

• A. Depends on organism
• B. Only sometimes
• C. Yes
• D. No

Answer: (C)

Cellular respiration relies on oxygen to make most of its ATP. The crucial step is oxidative phosphorylation, where electrons are passed along the electron transport chain and oxygen serves as the final electron acceptor. This allows the chain to keep pulling electrons, pumping protons, and driving ATP synthase to produce lots of ATP. Without oxygen, the electron transport chain grinds to a halt, NADH and FADH2 can’t be recycled to NAD+ and FAD, and ATP production via this pathway stops, leaving only a small amount of ATP from glycolysis. So, while glycolysis can occur without oxygen, the full cellular respiration process depends on oxygen to maximize ATP yield.

Cellular respiration relies on oxygen to make most of its ATP. The crucial step is oxidative phosphorylation, where electrons are passed along the electron transport chain and oxygen serves as the final electron acceptor. This allows the chain to keep pulling electrons, pumping protons, and driving ATP synthase to produce lots of ATP. Without oxygen, the electron transport chain grinds to a halt, NADH and FADH2 can’t be recycled to NAD+ and FAD, and ATP production via this pathway stops, leaving only a small amount of ATP from glycolysis. So, while glycolysis can occur without oxygen, the full cellular respiration process depends on oxygen to maximize ATP yield.