Either that substrate can actually dissociate from the active side before it is actually transformed into that product, and this reaction simply means we dissociate the complex back into the enzyme and the substrate. And the rate constant for this backward reaction is given by K minus one. But the other thing that can take place, and this is ultimately what we want to study in this lecture, is this reaction here. And in this reaction, that enzyme, when the substrate is inside the active side, the enzyme will catalyze the transformation of the substrate into the product and we form our product and the product dissociates from the active side. And the rate constant of this reaction is given by k two. Now, let's focus on just this reaction here.