Which process requires oxygen?

Which process requires oxygen?

• A. Aerobic respiration
• B. Anaerobic respiration
• C. Fermentation
• D. Glycolysis

Answer: (A)

Oxygen is required for the efficient production of ATP during cellular respiration because it acts as the final electron acceptor in the electron transport chain. In aerobic respiration, electrons are passed along a chain of proteins in the inner mitochondrial membrane, and oxygen accepts those electrons at the end, combining with protons to form water. This step keeps the chain moving, regenerates NAD+ and FAD so glycolysis and the citric acid cycle can continue, and powers the proton gradient that drives ATP synthase to make most of the cell’s ATP. Without oxygen, the chain halts, NADH builds up, and ATP production drops dramatically unless the cell switches to less efficient pathways like fermentation. While glycolysis can occur without oxygen, only aerobic respiration uses oxygen to yield the majority of ATP. Fermentation and anaerobic respiration do not use oxygen as the final electron acceptor.

Oxygen is required for the efficient production of ATP during cellular respiration because it acts as the final electron acceptor in the electron transport chain. In aerobic respiration, electrons are passed along a chain of proteins in the inner mitochondrial membrane, and oxygen accepts those electrons at the end, combining with protons to form water. This step keeps the chain moving, regenerates NAD+ and FAD so glycolysis and the citric acid cycle can continue, and powers the proton gradient that drives ATP synthase to make most of the cell’s ATP. Without oxygen, the chain halts, NADH builds up, and ATP production drops dramatically unless the cell switches to less efficient pathways like fermentation. While glycolysis can occur without oxygen, only aerobic respiration uses oxygen to yield the majority of ATP. Fermentation and anaerobic respiration do not use oxygen as the final electron acceptor.