A sterical correlation of the amino acids to their anticodon nucleotides is given. The main principle is the intercalation of the amino acid and the binding of the aliphatic amino acid hydrogen atoms through hydrogen bonds to the π-electrons of the bases. The amino groups of the bases and the ribose phosphate chain are additional binding sites for the amino acid. The strength of these hydrogen-π bonds is considerably increased by the protonation of the carboxyl group of the amino acid. Such a protonation occurs in esterification processes and gives in these reactions the possibility of an activated complex where the proposed complementarity is also energetically favoured. Evolutionary considerations show an uncomplicated way from the chemical reactions of prebiologically formed organic molecules to a living system.