krebs cycle

steps 1 and 2

Citrate synthase turns acetal CoA and oxaloacetate into citrate then aconitase isomerizes citrate into isocitrate

citric acid cycle step 3

oxidative decarboxylation of isocitrate by by isocitrate dehydroxylate. turns isocitrate into alpha-ketoglutarate one NADH and a CO2 regulated by the cells ATP levels

citric acid cycle step 4

oxidative decarboxylation of alpha-ketoglutarate by alpha-ketoglutarate results in succinyl CoA an NADH and another CO2 lost. regulated by the amount of NADH in the cell.

citric acid cycle step 5

succinyl CoA synthetase regerates acetyl CoA it turns succinyl CoA into succinate and a HS-CoA and also produces a GTP

citric acid cycle step 6

succinate dehydrogenase turns succinate into furmate and an FAD into FADH2, it does FADH2 not NADH because NADH would require too much energy

citric acid cycle steps 7 and 8

fumarase hydrates fumarate turning it into malate, then malate dehydrogenase oxidizes malate into oxalate and reduces NAD+ to NADH. oxoacetate is needed in the start of the cycle: how the cycle is cyclical