So we see that our electrons, the high energy electrons, are accompanied by hydrogen ions. So that means when our NAD plus accepts those two electrons, it also accepts a single h plus ion to form the reduced version of our Nicotinemide adenine Dinucleotide. And when Fad plus accepts those two electrons, it accepts not one, but two h ions to form the reduced version of Flavin adenine Dinucleotide, our Fadh two. Now, in which processes do we actually form our NADH and how is it exactly used to synthesize our ATP molecules? Well, NADH molecules are formed in glycolysis, which takes place in the cytoplasm of the cell. And NADH molecules are also formed in pyruvate decarboxylation and in the citric acid cycle, also known as the crept cycle, which takes place in the mitochondrial matrix.