CO2 Yield from Glucose Oxidation

Steps:

• One glucose molecule (C6H12O6) is fully oxidized in aerobic respiration to produce 6 CO2 molecules via glycolysis, pyruvate decarboxylation, and the Krebs cycle.
• The balanced equation is C6H12O6 + 6O2 → 6CO2 + 6H2O + energy.
• For two glucose molecules, double the CO2 output: 6 × 2 = 12.
• This accounts for complete aerobic breakdown in eukaryotes or prokaryotes.

Why D is correct:

• The overall reaction for aerobic respiration dictates 6 CO2 per glucose, so 12 for two, per the stoichiometry of C6H12O6 + 6O2 → 6CO2 + 6H2O.

Why the others are wrong:

• A. 2: Underestimates; even anaerobic fermentation produces less, but aerobic yields 6 per glucose.
• B. 4: Incorrect; ignores full Krebs cycle contributions beyond initial steps.
• C. 6: Matches one glucose only, not two.

Final answer: D