One of these molecules is the substrate of soluble liver antigen, a target of autoimmune hepatitis. Modification of the Levitt pair changes which “identity set” these molecules are part of. The high fidelity of the synthesis and subsequent recognition of these kilodalton-sized molecules motivated (-5[1])the theory of kinetic proofreading. Orthogonal systems for processing these molecules are often based on M. jannaschii’s reduced set of synthases and can ligate them with “unnatural” components. (10[1])TetM and (10[1])TetO are “protectors” that help these molecules bind in the presence of tetracyclines and have homology to EF-Tu. (-5[2])Each of these L-shaped (10[1])molecules (10[1])is paired with an AARS (10[1]-5[1])that “charges” (10[1])them with a (10[1])specific (10[2])zwitterion (10[2])before they enter (10[1])the A site. (10[1])For 10 points, (10[1])name these molecules that enter (10[1])the ribosome carrying the amino acid (-5[1])for a given codon. (10[1])■END■ (10[4])