Answer:
4
Step-by-step explanation:
The reactions are:
Glycolysis: 1 glucose ⟶ 2 pyruvate
Link reaction: 2 × [1 pyruvate ⟶ 1 acetyl CoA]
Citric acid cycle: 2 × [1 AcetylCoA ⟶ 2 CO₂]
Now, add the reactions, cancelling species that occur on both sides of the reaction arrow,
1 glucose ⟶ <u>2 pyruvate
</u>
<u>2 pyruvate</u> ⟶ <u>2 acetyl CoA
</u>
<u>2 AcetylCoA </u>⟶ 4 CO₂
<em>Overall</em> : 1 glucose ⟶ 4 CO₂
For each mole of glucose, four molecules of CO₂ are released in the citric acid cycle.