So this reaction no longer takes place or takes place at a low rate. Why? Well, because we have a deficiency in this enzyme and so that will begin to decrease the levels of Arginine. By decreasing the levels of this molecule, we decrease the levels of the reactant in this reaction. And that drives the rate of reaction five to the ground. And so we no longer are producing the urea and we're no longer generating the ornathan that we need for step number two, because in step number two, this carbon well phosphate combines with the ornithine to form the citrulline.