When there is a rise in calcium concentrations in the cytoplasm of the skeleton muscle cells, there's also rise in calcium levels in the matrix of the mitochondria. And that calcium will go on and stimulate the phosphatase to actually defosphorylate this molecule, use a water molecule to hydrolyze this bond, releasing that inorganic orthophosphate and activating our Pyruvate dehydrogenase complex and that will stimulate this process. It will basically continually transform the Pyruvate into acetyl coenzyme A and that will commit the molecule to undergoing the citric acid cycle which is ultimately used to generate ATP molecules along the proteins of the inner mitochondria, along that electron transport chain. So this is how we basically inhibit or activate the activity of Pyruvate dehydrogenase complex. Now, the final thing that I'd like to focus on is how there are certain cells of our body which also respond to hormones. And these hormones essentially stimulate or in some cases don't stimulate the activity of Pyruvate dehydrogenase complex.