So if Km is small, the enzyme binds tightly to the substrate and the substrate will tend to remain bound to the active side. So we see that we can actually give two different meanings to the Mikalus constant. So physiological meaning number one is the Km describes the concentration of that substrate. When the enzymes activity, the velocity of the enzyme is exactly half of the maximum velocity and at this point, exactly half of the active sites on the enzyme mixture in the enzyme mixture are actually filled with the substrate. Now, and this must be emphasized, we can only use this second meaning as long as we remember that we made this assumption because this entire work is only meaningful if this is actually used. So if this is true, if K one is much greater than K two.