So this is the equation that describes the rate at some concentration of Es. Now, what exactly is the equation that gives us the maximum velocity, the maximum rate v max of that particular enzyme? Well, to find what the maximum rate is V max, we have to basically assume that all the enzymes, all the initial enzymes that we begin with, contain all the active sites that are completely filled with the substrate. So when all the active sites are occupied by the substrate, what that basically means is the enzyme substrate complex concentration, Es, is equal to the initial total concentration of that enzyme. So to see what we mean by that, let's take a look at the following diagram. So let's suppose initially inside Arabica, before we added the substrate, we contained three of these identical enzymes.