Now, glycolysis also forms our two NADH molecules and each one of these NADH molecules eventually end up in the electron transport chain. And because we have two NADH molecules form in glycolysis, we form two times two. So four ATP molecules, for a total of six ATP molecules form either directly or indirectly by glycolysis. Now let's move on to Pyruvate carboxylation. So this process does not form ATP molecules directly but it forms two NADH molecules. And remember, a single NADH molecule formed in the mitochondrial matrix produces three ATP molecules on the electron transport chain.