In the Krebs cycle, acetyl-CoA, derived from the breakdown of carbohydrates, fats, and proteins, combines with oxaloacetate to form citrate. This is followed by a sequence of eight enzymatic reactions that progressively oxidize citrate, releasing two molecules of CO₂, generating three molecules of NADH, one FADH₂, and one GTP (or ATP) per cycle turn. Several intermediates, such as α-ketoglutarate and succinyl-CoA, are formed and converted through oxidation, decarboxylation, and hydration reactions. The cycle concludes by regenerating oxaloacetate, enabling continuous operation as long as substrates and cofactors are available.
