So we have to be able to move these acetylco enzyme A molecules from the matrix into the cytoplasm cell to actually initiate the process of fatty acid synthesis. Now, there's a problem with moving acetyl coenzyme A molecules across the membrane of the mitochondria. And the problem is it's water soluble. So if we look at the acetyl coenzyme A molecule, the coenzyme a component of the acetyl coenzyme A molecule prevents that acetyl group from actually moving across the inner mitochondrial membrane. And so to ultimately allow the movement of that acetyl coenzyme A molecule across, we have to remove that coenzyme A. And so what happens is we transfer this CETL group onto oxalo acetate in the process that is catalyzed by citrate synthase to form the citrate molecule.