Place the following events of glucose catabolism in the correct order, placing a 1 by the first event, a 2 by the second, and so forth.
________Electrons are passed between electron carriers in the inner mitochondrial membrane, and hydrogen ions are pumped into the intermembrane space.
________ATP is generated in the cytosol by substrate-level phosphorylation; NADH is generated as well. Hydrogen ions pass through the channel of ATP synthase and ATP is released from the enzyme.
________Acetyl-CoA is combined with oxaloacetate to form citrate.
________ATP is consumed to split glucose into two three-carbon compounds.
________Pyruvate loses a carbon, forming acetyl-CoA, carbon dioxide, and NADH.
________Citrate undergoes a series of oxidation-reduction reactions that generate ATP, NADH, and FADH2.