#成长值抽奖赢iPhone17和周边 #十二月行情展望 What exactly should I do today? The enzymes involved in the urea cycle are all located within the mitochondria. The primary structure of a protein refers to the sequence of amino acid residues in the polypeptide chain. Because the sequence of the polypeptide chain in a protein molecule contains all the information required to automatically form a complex three-dimensional structure (i.e., the correct spatial conformation), the primary structure determines its higher-level structure.