The twenty standard amino acids are either used to synthesize proteins and other biomolecules, or oxidized to urea and carbon dioxide as a source of energy. Such modifications can also determine the localization of the protein, e.g., the addition of long hydrophobic groups can cause a protein to bind to a phospholipid membrane. These modifications are often essential for the function or regulation of a protein for example, the carboxylation of glutamate allows for better binding of calcium cations, and the hydroxylation of proline is critical for maintaining connective tissues and responding to oxygen starvation. Other amino acids contained in proteins are usually formed by post-translational modification, which is modification after translation in protein synthesis. Twenty amino acids are encoded by the standard genetic code and are called proteinogenic or standard amino acids. The process of such formation from an mRNA template is known as translation which is part of protein biosynthesis. They form short polymer chains called peptides or longer chains either called polypeptides or proteins. Just as the letters of the alphabet can be combined to form an almost endless variety of words, amino acids can be linked in varying sequences to form a huge variety of proteins.Īmino acids are the basic structural building units of proteins. Each different protein has a unique sequence of amino acid residues this sequence is the primary structure of the protein.

Proteins form via the condensation of amino acids to form a chain of amino acid “residues” linked by peptide bonds. This can vary in size from just a hydrogen atom in glycine, through a methyl group in alanine, to a large heterocyclic group in tryptophan.Īlpha-amino acids are the building blocks of proteins. The various alpha amino acids differ in which side chain (R group) is attached to their alpha carbon. These are molecules where the amino and carboxylate groups are attached to the same carbon, which is called the α–carbon. In biochemistry, this term refers to alpha-amino acids with the general formula NH2CHRCOOH. In chemistry, an amino acid is a molecule that contains both amine and carboxyl functional groups. This entry is from Wikipedia, the leading user-contributed encyclopedia.įor the structures and properties of the standard proteinogenic amino acids, see List of standard amino acids. Resins for Solid Phase Peptide Synthesis.

Mnemonic for hydrophobic amino acids