The Citric Acid Cycle

In the aerobic glycolysis, the metabolic way was ordered to be stopped when pyruvate ions were formed. In the aerobic conditions, glycolysis was the prelude of the citric acid cycle. Actually, the entry of pyruvate ions into this metabolic way is its beginning. The citric acid cycle is the final and general way of oxidation of molecules of fuel. It is also named Krebs’ cycle. The part played by Krebs’ cycle is to completely oxidize the acetyl coenzyme A (acetyl-CoA) into CO₂. Citrate ion results from the condensation of oxaloacetate with acetyl-CoA. The enzyme catalysing the isomerization is the aconitase and the reaction involves the cis-aconitate as intermediary. The aconitase does contain Fe atoms which are not linked to a heme rest. Reaction is the sole step of the Krebs’ cycle which directly gives a rich-energy phosphate bond.