So when the substrate essentially dissociates from the active site we produce back this enzyme and a substrate that K minus one. K one is basically the association, the formation of this enzyme substrate complex. And K two is the rate constant for this reaction, the dissociation of the enzyme substrate complex into the product molecule and that enzyme. So we were able to basically derive this equation in that lecture and we're going to use this equation in just a moment to basically give the Michelin constant a second physiological meaning. This is the important assumption we want to make. Let's suppose that the dissociation of the enzyme substrate complex is much more rapid.