e1=Citrate synthase&e2=Aconitase&e3=Isocitrate dehydrogenase&e4=Alpha-ketoglutarate dehydrogenase&e5=Succinate thiokinase or succinyl CoA synthase&e6=Succinic dehydrogenase&e7=Fumarase&e8=Malic dehydrogenase&e9=&e10=&e11=&c1=&c2=&c3=&c4=See key points.&c5=&c6=&c7=&c8=&c9=&c10=&c11=&k1=Large free energy (from breaking the thioester bond) drives this hydrolysis.&k2=Movement of the hydroxyl group to C-2 eventually allows for two keto-acid decarboxylations.  
Enzyme contains a non-heme iron sulfur center.  This is a rare instance when a non-heme center is not involved in a redox reaction.&k3=Two forms of the enzyme use NAD and NADP.  The NAD form is physiologically important, is found only in mitochondria, and requires allosteric activation by ADP&k4=Several cofactors in the complex: thiamine pyrophosphate, lipoic acid, and FAD. NAD is technically a substrate, although it is occasionally cited as a cofactor.&k5=GTP can readily transfer a phosphate to ADP, as can ATP to GDP using the enzyme nucleoside diphosphokinase.&k6=This enzyme is bound to the inner mitochondrial membrane.&k7=&k8=This reaction would proceed backward if acetyl CoA didn't feed into the cycle to keep it moving forward.&k9=&k10=&k11=&