So there is a difference in motion. For eukaryotic, we have our dynamic proteins that basically use our ATP energy source to slide along our microtubules, creating a bendinglike motion. So for eukaryotic case, we have a bendinglike motion, for our prokaryotic case, we have our rotating motion. So remember, these proton rings rotate as a result of the movement of protons down the electrochemical gradient, and that rotates this entire flagella in the counterclockwise fashion if we're moving forward and clockwise, if we want to change direction. Now, the energy source for our eukaryotic flagella is basically ATP. However, for the case of prokaryotes, we don't use ATP directly.