Question

Throughout history, many sources of chemical and radiation have been shown to alter DNA sequences via particular mutations that insert an extra nucleotide pair into DNA. Based on the alteration, what is the end likely outcome regarding protein synthesis?

Answer 1

When a extra pair of nucleotide is incorporated in between the DNA sequence of a gene then the synthesis of protein is disturbed. as the pair of nucleotide is incorporated, it will Shift the overall frame by one base pair, it causes the change in all the codons present nest to the site of insertion.

for example NORMAL SEQUENCE IS

5' ACG TCG ATC GAT CGA TCG ATC GAT 3'

3' TGC AGC TAG CTA GCT AGC TAG CTA 5'

on insertion of one pair of nucleotide (shown in red colour), it will lead to shift in overs all frame as follows

5' ACG TCG AAT CGA TCG ATC GAT CGA T 3'

3' TGC AGC TTA GCT AGC TAG CTA GCT A 5'

thus during translation the amino acid sequence will be altered or changed starting from the codon where insertion taken place.