5. Base composition of the triplets coding for some amino acids were revealed using mixed copolymers of rNa The composition of an RNa synthesized using polyribonucleotide phosphory lase depends on the proportion of each NDP present in the reaction mixture Investigation of the identity and quantity of the amino acids incorporated into the polypeptides in response to random polymers of rNa made from various ratios of NDPs can reveal the nucleotide composition(but not exact sequence) of the triplets corresponding to certain amino acids5. Base composition of the triplets coding for some amino acids were revealed using mixed copolymers of RNA • The composition of an RNA synthesized using polyribonucleotide phosphorylase depends on the proportion of each NDP present in the reaction mixture. • Investigation of the identity and quantity of the amino acids incorporated into the polypeptides in response to random polymers of RNA made from various ratios of NDPs can reveal the nucleotide composition (but not exact sequence) of the triplets corresponding to certain amino acids