Answer to Question #158407 in Cell Biology for Yessi

Question

why does the change in only one DNA base of a gene does not always result in a different protein being produced by the gene

Answer 1

CHANGE IN DNA BASE GENE

Abstract: Base substitution involves swapping one nucleotide for another during DNA replication, base substitution can lead to three different sub-categories of mutation; missense, nonsense and silent mutation. On this case we are going to focus on nonsense mutation.

Nonsense mutations occur when the altered codon prematurely terminates synthesis of a protein molecule. The change in one DNA base of a gene does not result in a different protein being produced by the gene because the properties and structure of the substituted DNA are similar to the original base and will most likely have little effect on the resultant protein functional structure.

The genetic mutation in a DNA sequence results in a shorter, unfinished protein product. During protein formation, DNA nucleotides sequences are read three nucleotides at a time (codon).Each codon corresponds to a specific amino acid or stop signal. Stop codons are also called nonsense codons because they do not code for an amino acid and instead signal the end of protein synthesis. When the mutated sequence is translated into a protein the resulting protein is incomplete and shorter than normal. Most nonsense mutations result in non-functional proteins.

References:

2014 nature education.

Academic.oup.com

Dr.Noel sturm 2019.