Now, the long chain basically acts on fatty acids that contain anywhere from twelve to 18 carbon atoms. The medium chain acts on fatty acids, which contain anywhere from four to 14 carbon atoms. And we're only talking about even number of carbon atoms. And the short chain one acts on fatty acids that contain four or six carbon atoms. So, as we discussed in this particular section, once the two electrons are transferred onto Fadh two, which is actually a prosthetic group found on this enzyme, the two electrons are then moved onto ETF, then onto an enzyme we call ETF dehydrogenase. And then finally, they are used to actually reduce Ubiquinone into Ubiquinol.