Question

A researcher creates random copolymers by mixing polynucleotide phosphorylase with

guanine and adenine nucleotides at a ratio of 5 guanine nucleotides to 1 adenine nucleotide.

What amino acids could be produced by this mixture, and in what theoretical proportions

would you expect them? (Hint: you need to figure out what codons you can make, in what

proportions, and then use that to figure out which amino acids you’d expect.)

Answer 1

The given Neuceotides are GGGGGA. (G-Guanine, A-Adenine, T-Thymine, C-Cytosine)
During the process of translation, the above nucleotide gets converted to TCCCCC, as T is the complementary pair of A, and C is the complementary pair of G.

Following are the possible Codon sets that can be obtained using TCCCCC, along with their respective amino acids.
1. TCC(serine) / CCC(proline)
2. CTC(leucine) / CCC(proline)
3. CCT(proline) / CCC(proline)

From the above results, the following ratio of the amino acid is obtained.
i.e. Proline : Serine : Leucine :: 4 : 1 : 1
This is the theoritical proportions expected.