Question

Har Gobind Khorana and his colleagues performed numerous experiments translating synthetic mRNAs. In one experiment, an mRNA molecule with a repeating UG dinucleotide sequence was assembled and translated.
If the genetic code were a doublet code instead of a triplet code, how would the result of this experiment be different?

Accepted Answer

Understand the concept of the genetic code: The genetic code is a triplet code, meaning that three nucleotides (codons) specify one amino acid. If the code were a doublet code, only two nucleotides would specify one amino acid, reducing the number of possible codons. Analyze the repeating UG dinucleotide sequence: The mRNA sequence in the experiment alternates between U and G, forming a repeating pattern (UGUGUG...). In a triplet code, codons would be read in groups of three nucleotides, such as UGU, GUG, etc. In a doublet code, codons would be read in groups of two nucleotides, such as UG, GU, etc. Determine the implications of a doublet code: A doublet code would result in fewer possible codons $$(4^2 = 16 $$codons) compared to a triplet code $$(4^3 = 64 $$codons). This would limit the diversity of amino acids that could be encoded, as there are 20 amino acids in the standard genetic code. Predict the translation outcome: In a doublet code scenario, the repeating UG sequence would produce fewer distinct codons, potentially leading to a simpler or repetitive polypeptide sequence. For example, UG and GU might correspond to fewer amino acids, resulting in a less complex protein. Compare to the triplet code result: In the actual experiment with a triplet code, the repeating UG sequence would produce a more diverse set of codons and a more complex polypeptide. This highlights the importance of the triplet code in encoding the full range of amino acids and generating functional proteins.

비슷한 문제에 대한 검증된 영상 답변:

주요 개념

Genetic Code

Triplet Code vs. Doublet Code

Translation Process