And that's exactly where ATP synthase comes into play. So ATP synthase is basically a complex of proteins that create channels that allow the H plus ions to flow through these regions. So basically, our H plus ions begin to travel down their electrochemical gradient from a high concentration to a low concentration from a lot of charge to a very little charge. And as the H plus ions flow this way into the mitochondrial matrix, the ATP synthase also basically combines ADP adenosine diphosphate and a phosphate group to synthesize our ATP molecules. So basically, for a single NADH that is formed in either the citric acid cycle or pyruvate decarboxylation, one NADH produces three ATP molecules. However, if we examine the NADH molecule that is formed in glycolysis to actually get from the cytoplasm where glycolysis takes place and into the mitochondrial matrix, the NADH molecule has to transport via our mitochondrial inner and outer membrane and that requires energy.