Now Pyruvate under aerobic conditions will go into the mitochondria and the citric acid cycle will take place. And that will not only generate many more ATP molecules, but perhaps even more importantly, it will regenerate those NAD plus coenzymes that are essentially used up in step six of glycolysis. So remember, in glycolysis, in step six we essentially use up NAD plus coenzymes. And the process of glycolysis itself does not actually regenerate these NAD plus coenzymes. And if we don't regenerate the NAD plus coenzymes because we have a limited supply of these coenzymes in our cells, glycolysis will essentially end very quickly. And so under aerobic conditions, we use the citric acid cycle to regenerate those NAD plus molecules.