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Title: Explain why the insertion of 3 nucleotides is less likely to result in a deleterious effect than an insertion? Post by: leighbrown on Jul 17, 2013 This is a microbiology question referring to genetics, biotechnology, and recombinant DNA. I think it has something to do with a codon. Please help!
Title: Explain why the insertion of 3 nucleotides is less likely to result in a deleterious effect than an insertion? Post by: rmefaj on Jul 17, 2013 As you probably know, a codon is a sequence of 3 nucleotides along an mRNA molecule. Each codon specifies a particular amino acid. The insertion of 3 nucleotides into an mRNA strand will more than likely result in the addition of another amino acid, which may not necessarily cause any significant damage to the polypeptide (silent mutation). However, the insertion of one base into the mRNA strand will result in a frameshift muation, in which the reading of the code is shifted by one base. I will try to give an example.
Consider the following sentence: THE FAT CAT ATE THE RAT The insertion of a base will result in the following: THE FAT ACA TAT ETH ERA T Here, the insertion of "A" into the sentence represents a nonsense mutation. This can result in the premature termination of the polypeptide. Hence, the polypeptide will be shorter than the one encoded by the normal gene. I hope this makes sense! |