A point mutation changes a codon in the mRNA for an enzyme from GCC to GCA. Why is there no change in the amino acid order in the protein?

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All right. Hi, everyone. So this question says in a certain gene, a point mutation changes a code on in the MRN A from UUU to UUC. Despite this mutation, no change occurs in the sequence of amino acids in the resulting protein. Explain why. So very quickly, right? We have two different coons that we're discussing. In this question, we have Uuu and UUC codons if you recall are groups of three nucleotides that together code for one amino acid during translation. So to enter or to understand the answer to this question, it's important to recall one specific property about the genetic code, the genetic code, if you recall is a sequence essentially or rather a list of different codons possible and what amino acid they code for. And so one very important property of the genetic code is known as redundancy. Now, you may have also heard the genetic code described as degenerate. So just to be clear redundancy and degeneracy describe the same exact property of the genetic code. So once again, what does it mean? Right. Well, essentially the redundancy of the genetic code essentially says that multiple coons can code for the same amino acid. And just to go ahead and very quickly clarify one coon is always going to code for one amino acid. However, multiple coons can and do code for the same amino acid. And so according to our genetic code, Uuu and UUC are examples of coons that both will result in phenyl alanine. So there has been a change in the MRN a sequence but the end result is the same right, the same amino acid is created after the mutation. And so because the amino acid that's resulting is not actually changing, this is known as a synonymous mutation. Now oftentimes the variations in codons that result in synonymous mutations occur in the third nucleotide of the codon. That's why it's known as the wobble base of a codon. Now, the redundancy of the genetic code is meant as a form of protection from certain mutations in nature, right? If certain mutations can result in the same amino acid, then it's less likely for that mutation to harm the final protein product. And so that brings us now to our final answer. So I went ahead and pre wrote the final answer. So I'm just going to go ahead and scroll down. So you can see it, the final answer reads as follows the mutation from UUU to UU is a synonymous mutation as both codons code for the same amino acid pheno alanine due to the redundancy of the genetic code. And so with that being said, thank you so very much for watching. And I hope you found this helpful.

A point mutation changes a codon in the mRNA for an enzyme from GCC to GCA. Why is there no change in the amino acid order in the protein?

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Key Concepts

Codon Redundancy

Point Mutation

Amino Acid Sequence