But if we continue adding substrate molecules so that we add, let's say, 100 substrate molecules, then all the active sites and all the enzymes will be filled. And that means the entire activity of our mixture of enzymes will be at a maximum velocity. And that's exactly what this graph actually represents. So the Y axis is the enzyme activity, also called the enzyme velocity. And the X axis is the substrate concentration. So basically, this dashed line represents the maximum velocity at which that enzyme or the mixture of enzymes will actually operate.