Pathways Involved in Protein and Amino Acid Metabolism in Chronic Kidney Disease. The tricarboxylic acid (TCA) cycle comprises a series of chemical reactions that can metabolize amino acids. Amino groups are the products of amino acid deamination. Urea is synthesized through the urea cycle in the liver from the oxidation of amino acids or from ammonia. These mechanisms serve to trap and neutralize the highly volatile and toxic ammonia that is released from α-amino groups on transamination of amino acids in the liver. #Pathophysiology #Nephro #Nutrition #CKD #ProteinMetabolism #AminoAcidMetabolism #Pathways #NEJM