Question

Given: RNA codon chart and DNA sequence of the enzyme. Make 2 amino acid changes:1. Proline to Glycine2. Tyrosine to Phenylalanine a) what are the steps required to make these changes, in order? b) transcribe the following DNA sequence into mRNA: 3’ TAC CCC GAT AAA ATA CAT TTA GGA TCG CGA TGG TAT 5’

Answer 1

1. To change from Proline to Glycine

Step 1: Change the DNA of proline

Proline has the following four condons: CCG, CCC, CCU, and CCA.

And the Glycine codons are: GGT, GGG, GGA and GGC

So if the codons of Proline can be changed, C to G, we will have CCG, CCC, CCU, and CCA.

Which are the same as the codons of Glycine, when the tRNA translates, these will be amino acids of Glycine.

2. To change Tyrosine to Phenylalanine

The codons of Tyrosine are: UAU, UAC, UAA and UAG

Whereas the codons for Phenylalanine are: UUU, UUC, UUA and UUG

change the A to U in Tyrosine to get Phenylalanine

So the final Tyrosine codons will be: UUU, UUC, UUA and UUG.