Take a look at a codon table that specifies which amino acids are translated from a sequence of three mRNA nucleotides. Some of these nucleotide triplets specify the same amino acid, such as GUU, GUC, GUA and GUG all code for the amino acid Valine. When might this redundancy that is built into the genetic code be of importance? (Hint: Consider potential mutations in a section of DNA that codes for a particular protein.)
The Correct Answer and Explanation is :
The redundancy in the genetic code, known as codon degeneracy, allows for multiple codons to code for the same amino acid. This characteristic can be of importance, especially in the context of mutations in DNA sequences that encode for proteins. For example, consider a mutation in a DNA sequence that changes one nucleotide, resulting in a change in the corresponding mRNA codon. If this mutation changes the codon to another triplet that still codes for the same amino acid, the mutation would be classified as a silent mutation. This type of mutation generally has no effect on the function of the protein because the same amino acid is incorporated into the polypeptide chain.
This redundancy plays a critical role in reducing the potential negative impact of mutations, particularly point mutations (where a single nucleotide is changed). In cases where a mutation does not alter the amino acid sequence of the resulting protein, the protein’s function remains unchanged, thereby safeguarding the organism from potentially harmful effects.
However, in cases where a mutation leads to the incorporation of a different amino acid (for example, changing a codon for one amino acid into one that codes for a different amino acid), the redundancy can still be important. It may minimize the effect of the mutation by replacing the amino acid with one that has a similar chemical property or function, which can reduce the impact on the protein’s activity. For instance, a change from one hydrophobic amino acid to another hydrophobic one may not significantly disrupt the protein’s structure or function.
Therefore, the redundancy in the genetic code serves as a buffer against harmful mutations, helping to maintain protein function even when genetic changes occur.
Now, I will generate a codon table image for you.
Here is the codon table showing how different mRNA codons correspond to amino acids. This redundancy in the genetic code can be very important in reducing the effects of mutations, as it helps minimize changes to the resulting protein’s structure and function. Let me know if you need further clarification!