Question

The last electron acceptor in ETS (Electron Transport System) is:

• A. Oxygen (\( \mathrm{O_2} \))
• B. NADH
• C. FADH
• D. Carbon dioxide (\( \mathrm{CO_2} \))

Hint:

The equation for the final step in ETS is: \[ \mathrm{4H^+ + 4e^- + O_2 \to 2H_2O}. \] This process is vital for maintaining the proton gradient for ATP synthesis.

Answer 1

The Correct Option is A

Oxygen (\( \mathrm{O_2} \)) acts as the terminal electron acceptor in the Electron Transport System (ETS). The sequence of events is: Electrons traverse a chain of complexes embedded within the inner mitochondrial membrane. At the chain's conclusion, electrons unite with \( \mathrm{O_2} \) and protons (\( \mathrm{H^+} \)) to yield water (\( \mathrm{H_2O} \)). This chemical transformation sustains the proton gradient vital for ATP generation.Consequently, oxygen is indispensable for the effective synthesis of ATP during aerobic respiration.