So let's suppose we have some type of very long chain fatty acid. Let's suppose our N value here is 16 or greater so that this entire molecule contains at least 20 carbon atoms. Now, in step one, we basically transform this single bond between carbon number two and three into a double bond. And at the same time, we basically reduce the Fad molecule into an Fadh two molecule. Now, this group, the Fad, is actually found bound to the acyl coenzyme a dehydrogenase. So this is a flavor protein dehydrogenase, and it's different.