Question

The genetic code was originally deciphered, in part, by experiments in which synthetic polynucleotides with repeating sequences were used as mRNAs to direct protein synthesis in cell-free extracts. Under these conditions, ribosomes could be made to start translation anywhere within the RNA molecules, with no start codon necessary. What peptide would be made by translation from a synthetic mRNA made entirely of adenine (poly-A)?

Answer 1

A polymer composed of lysine (K) amino acids

Step-by-step explanation:

During translation, the information encoded in each triplet of nucleotide bases, or codon, in the mRNA sequence is used to specify a particular amino acid of the nascent polypeptide chain. In this case, the AAA codon encodes the basic amino acid lysine (K), and therefore an mRNA sequence composed of polyadenine (polyA) will invariably produce a polymer of lysine (K) amino acids.