What is the fate of NADH after it donates its electrons to the electron transport system? A) NAD⁺is excreted from the cell and sent to the liver for final degradation. B) NADH is used for cellular biosynthesis. C) NAD⁺is re-reduced by the TCA cycle or glycolysis and returns to electron transport system, where the process is repeated. D) NAD⁺is fed into the TCA cycle for oxidation of CO₂.

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Quizplus · Accepted Answer

After donating its electrons to the electron transport system, NADH is re-reduced by the TCA cycle or glycolysis and returns to the electron transport system, where the process is repeated. This is known as the NADH shuttle system. NADH cannot be used for cellular biosynthesis, and it is not excreted from the cell. It is also not fed directly into the TCA cycle for oxidation of CO2.

What Is the Fate of NADH After It Donates Its