And because enzymes ultimately stabilize the energy and the structure of the transition state, these are very, very potent, very effective inhibitors. So let's take a look at two examples. So let's begin by examining an enzyme found in bacterial cells known as proline raysimase. And proline raysimase basically catalyzes the transformation, the isomerization reaction of Lproline into Dproline. Now, the difference between Lproline and Dproline lies in the stereochemistry of this carbon. On this particular molecule, the H atom points into the board.