a. The genetic code was elucidated with polyribonucleotides synthesized enzymatically using polynucleotide phosphorylase. Given a supply of polynucleotide phosphorylase, any desired ribonucleoside monophosphates, ribonucleoside diphosphates, the genetic code, and an in vitro translation system, how would you make a polyribonucleotide that could serve as an mRNA coding predominately for many the residues and a small number of Leu and Ser residues.

b. What other amino acids (if any) would be coded for by this polyribonucleotide, but in small amounts?