Now, before we actually go into our discussion of the structure of this enzyme, the final thing that I'd like to focus on in this lecture is the fact that aspartate transcarbomolase observes cooperative behavior. So, like most allosteric enzymes, atcase actually exhibits cooperativity. And so what that means is the binding to one side affects the binding affinity of the other sides on that same enzyme. And if we graph the relationship between the rate at which we produce this product molecule, the ncarbon oil as pertain with respect to the concentration of the substrate, the aspartate, as shown in this diagram, we're going to see not the typical Michaela SmithIn curve, but we're going to see the sigmoidal s shape curve. And that's because this enzyme and allosteric enzymes in general, observe cooperative behavior. Now, what do we mean by cooperative behavior?