The Es can basically go in two different ways. It can either go on and form this product, which is basically this equation number one that we described here, or it can go back and reform these two reactants. And equation three gives us the dissociation of that substrate from that enzyme. So the rate of dissociation of the enzyme substrate complex is equal to the product of the reverse reaction, k minus one multiplied by this quantity here. Now, our Es complex doesn't only dissociate going this way, there's also a probability that it will dissociate going this way. And so when it dissociates going this way, we have K two multiplied by the concentration of Es.