The complete Krebs, truncated Krebs and glyoxylate cycles. Abbreviations: α-ketoglytarate -KGL, α-ketoglytarate dehydrogenase – KGDH, acetyl-CoA – Ac-CoA, aspartate – ASP, citrate-CIT, gluconeogenesis – GNG, glutamate – GLU, glycogene – GLYC, glyoxylate-Glyox, isocitrate – ISC, isocitrate lyase – ICL, malate-MAL, malate synthase – MS, oxalacetate – OAA, phosphoenolpyruvate – PEP, succinate-SUC, transaminases (aminotransferases) – TRAM. The truncated Krebs cycle includes the OAA + GLU -> ASP + KGL reaction that is catalyzed by glutamate-glyoxylate-aminotransferase [58, 59]. TRAM reactions in mitochondria and cytosol are connected by common amino and keto acids. Thick lines represent rapid reaction steps, dashed lines – slow and easily inhibited steps, crossed out like is the blocked aconitase reaction, dotted like – malate synthase pathway that may have been recently lost in placental mammal common ancestor.