Now, if we take this new equation, this is equal to this and rearrange it and solve it for the concentration of the enzyme substrate complex, we get equation five. So we essentially bring this to this side and we bring this to our denominator here, and we get equation five. So the concentration Es is equal to E multiplied by S divided by Km. Now, for a moment, let's go back to that assumption that we made at the beginning. We said that we're looking at the reaction in its initial stages when the time is approximately equal to zero. Now, initially, when the time is approximately equal to zero, we have a lot of the substrate that hasn't actually bound onto the active side of the enzyme.