Fluorocitric acid is an organic compound with the chemical formula HOC(CO2H)(CH2CO2H)(CHFCO2H). It is a fluorinated carboxylic acid derived from citric acid by substitution of one methylene hydrogen by a fluorine atom. The appropriate anion is called fluorocitrate. Fluorocitrate is formed in two steps from fluoroacetate. Fluoroacetate is first converted to fluoroacetyl-CoA by acetyl-CoA synthetase in the mitochondria. Then fluoroacetyl-CoA condenses with oxaloacetate to form fluorocitrate. This step is catalyzed by citrate synthase. Fluorocitrate is a metabolite of fluoroacetic acid and is very toxic because it is not processable using aconitase in the citrate cycle. The enzyme is inhibited and the cycle stops working.