So polar resembles an intermediate in the reaction pathway and is therefore a highly potent, a highly effective inhibitor. It binds onto the active side because it resembles the bisepttrat analog that is formed as an intermediate in this particular reaction. And so once it binds onto the active side, it binds irreversibly and it does not let go. And that inhibits the activity of this enzyme. Now, once we actually bind the polyme molecule to the active side, that also that not only tells us where the active side is found, but it can also be used to basically study what kind of structural changes actually take place within the enzyme. As we'll see in just a moment.