Answer:
The correct answer is pyruvate.
Explanation:
In glycolysis, glucose is oxidized into two molecules of pyruvate by releasing electron which is accepted by NAD⁺ molecules. Glycolysis is the partial oxidation of glucose.
Then this pyruvate is fully oxidized into carbon dioxide in the Krebs cycle. So glucose is the electron donor in glycolysis and pyruvate is the electron donor in the Krebs cycle.
NAD⁺ which accepts electrons and gets reduced to NADH provides electron to the electron transport chain of mitochondria to generate ATP molecules.
Therefore once the electron donor glucose releases its electrons in glycolysis, it gets oxidized to a compound called pyruvate.
