Although we do generate a total of two GTP molecules, every time two Pyruvate molecules go into the citric acid cycle, we don't actually generate any ATP molecules. So why is that? Well, because the citric acid cycle is like the gateway for forming ATP molecules. Because once the citric acid cycle takes place and once we abstract all these electrons from these molecules, the carbon fuel molecules, these electrons, which are carried by NADH molecules and Fadh two molecules, can now move on to a series of proteins on the inner mitochondrial membrane we call the electron transport chain. And these series of proteins shown here basically allow the movement of these electrons down their potential gradient. And as electrons flow along these protein membranes on the membrane of the mitochondria, that generates a proton gradient across the two sides of the membrane.