CO2 Yield from Glucose Oxidation

Steps:

• One glucose molecule (C6H12O6) in aerobic respiration produces 6 CO2 through glycolysis (0 CO2), pyruvate oxidation (2 CO2), and Krebs cycle (4 CO2).
• The balanced equation is C6H12O6 + 6O2 → 6CO2 + 6H2O + energy.
• For two glucose molecules, double the CO2 output: 6 × 2 = 12.
• Total CO2 comes from complete oxidation of carbon atoms in glucose.

Why D is correct:

• Aerobic respiration oxidizes each glucose to 6 CO2 via the formula C6H12O6 + 6O2 → 6CO2 + 6H2O, so two glucoses produce 12 CO2.

Why the others are wrong:

• A. 2: Matches CO2 from pyruvate oxidation of only one glucose.
• B. 4: Matches CO2 from Krebs cycle of only one glucose.
• C. 6: Matches total CO2 from one glucose, not two.

Final answer: D