Finding common metabolic pathways, such as the tricarboxylic acid (krebs) cycle, in both prokaryotic and eukaryotic organisms is:

             There are difference in the TCA cycle of both prokaryotes and eukaryotes. In prokaryotes mitochondria is absent of TCA occurs in the cytosol. In eukaryotes it occurs in the mitochondria.
In this pathway, an NADP-dependent enzyme catalyzes the dehydrogenation of D-threo-isocitrate to 2-oxoglutarate, while eukaryotes employ an NAD+-dependent enzyme. Another difference is that while in most eukaryotes the conversion of (S)-malate to oxaloacetate is catalyzed only by an NAD-dependent enzyme, prokaryotes that employ this variation of the TCA cycle possess an alternative quinone-dependent enzyme.