Magnesium plays important roles in the structure and the function of the human body. It is important as a cofactor for enzymes that convert adenosine triphosphate to adenosine pyrophosphoric acid, with the subsequent release of energy. As a constituent of these enzymes, magnesium is essential to reactions involving the synthesis and metabolism of carbohydrates, lipids, proteins, and nucleic acids. Magnesium acts to relax muscles after calcium stimulates contraction. It is also necessary for the attachment of RNA to the protein-synthesizing ribosomal protein and for the synthesis, degradation, and stability of DNA. Magnesium has been termed a natural tranquilizer due to its therapeutic effect on the nervous symptoms of magnesium deficiency. These are essential for the activity of amino peptidases, which are secreted from the mucosal cells in the intestine to aid in the digestion of proteins.