Amino acids contain both amino and carboxylic acid functional groups. Proteins or Polypeptides are polymers of amino acids. Polyphosphates cause polymerization of amino acids into peptides. Pyridoxal phosphate promotes decarboxylation of amino acids. Glycine is one of the proteinogenic amino acids. Nonstandard amino acids are usually formed through modifications to standard amino acids. Cortisol stimulates degradation of (skin) collagen into amino acids. This polymerization of amino acids is what creates proteins. This peptide is synthesized in two steps from free amino acids. Thiamine is required for metabolism including that of glucose, amino acids, and lipids. It is essential for maintaining proper levels of amino acids which make up proteins. The majority of these consist of point mutations causing substitution of amino acids. The disease is attributed to deficiency in transport and metabolism of amino acids. CFTR is a glycoprotein with 1480 amino acids. The pathways for the synthesis of nonessential amino acids are quite simple.