<Tr> <Td> 10 / 0 </Td> <Td> Oxaloacetate + Acetyl CoA + H O </Td> <Td> Citrate + CoA - SH </Td> <Td> Citrate synthase </Td> <Td> Aldol condensation </Td> <Td> This is the same as step 0 and restarts the cycle . The reaction is irreversible and extends the 4C oxaloacetate to a 6C molecule </Td> </Tr> <P> Mitochondria in animals, including humans, possess two succinyl - CoA synthetases: one that produces GTP from GDP, and another that produces ATP from ADP . Plants have the type that produces ATP (ADP - forming succinyl - CoA synthetase). Several of the enzymes in the cycle may be loosely associated in a multienzyme protein complex within the mitochondrial matrix . </P> <P> The GTP that is formed by GDP - forming succinyl - CoA synthetase may be utilized by nucleoside - diphosphate kinase to form ATP (the catalyzed reaction is GTP + ADP → GDP + ATP). </P> <P> Products of the first turn of the cycle are one GTP (or ATP), three NADH, and two CO . </P>

In eukaryotes the enzymes of the citric acid cycle are found in the