You perform a cell free translation experiment like Nirenberg and Matthaei.You start with 60% C and 40% A.What relative amount of radiolabeled proline do you expect in the translated polypeptides?

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In the genetic code, proline is coded for by the codon CCx (where x can be any nucleotide). Out of the four possible codons (CCU, CCC, CCA, and CCG), only CCC codes for proline exclusively. Therefore, if the starting mixture has 60% C (which pairs with G to form the CCC codon), then we would expect 60% of the proline residues in the translated polypeptides to be labeled with radiolabeled proline. Since the starting mixture also has 40% A (which pairs with U to form another codon for proline, CCU), we would expect 40% of the proline residues in the translated polypeptides to be unlabeled. Therefore, the relative amount of radiolabeled proline in the translated polypeptides would be 60% of 60%, or 36%.

You Perform a Cell Free Translation Experiment Like Nirenberg and Matthaei.You