Which molecule acts as the final electron acceptor in aerobic respiration?

Which molecule acts as the final electron acceptor in aerobic respiration?

• A. NAD+
• B. FAD
• C. Oxygen
• D. Water

Answer: (C)

In aerobic respiration, electrons are passed along the electron transport chain and are ultimately accepted by oxygen. Oxygen’s role as the final electron acceptor is crucial because it has a high affinity for electrons and, with protons, is reduced to water, which keeps the chain moving and powers ATP synthesis via the proton gradient. NAD+ and FAD act as electron carriers earlier in the pathway, delivering electrons to the chain as NADH and FADH2; they are not the final acceptor. Water is the product formed when oxygen accepts those electrons and protons. Without oxygen, the chain stalls and ATP production drops dramatically.

In aerobic respiration, electrons are passed along the electron transport chain and are ultimately accepted by oxygen. Oxygen’s role as the final electron acceptor is crucial because it has a high affinity for electrons and, with protons, is reduced to water, which keeps the chain moving and powers ATP synthesis via the proton gradient. NAD+ and FAD act as electron carriers earlier in the pathway, delivering electrons to the chain as NADH and FADH2; they are not the final acceptor. Water is the product formed when oxygen accepts those electrons and protons. Without oxygen, the chain stalls and ATP production drops dramatically.