But in this particular case, the H atom is coming out of the board. And so that's the difference between Lproline and Dproline. And proline raysimase basically catalyzes the transformation of these two molecules back and forth. Now, if we examine the transition state when going from Lproline to Dproline, this is what we see. This is the structure of that high energy transition state. And notice that in this transition state, this carbon atom has planar.