Question

A human cell has 5 glucose molecules, 2 pyruvate molecules and 1 acetyl-CoA. If oxygen is not available, how many ATP would be generated when the cell wants to use these different molecules to generate energy?

Answer 1

Since oxygen is required in the electron transport chain the cell is unable to break down glucose past pyruvate. This means that both pyruvates and acetyl-CoA are unable to help produce further ATP. The cell is still able to break down the 5 glucose molecules using glycolysis however instead of producing pyruvate its final product is lactic acid. Since each glucose is can create 4 ATP (net 2 ATP) five glucose molecules would produce 20ATP net (10ATP).