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.

How did the polypeptide composition help confirm the triplet nature of the genetic code?

Key Concepts

Triplet Nature of the Genetic Code

The genetic code is composed of codons, which are sequences of three nucleotides that correspond to specific amino acids. This triplet nature allows for 64 possible combinations (4^3) from the four nucleotides (A, U, G, C), providing a sufficient number of codons to code for the 20 amino acids used in protein synthesis. Understanding this concept is crucial for interpreting how mRNA sequences translate into polypeptides.

Synthetic mRNA and Translation

Synthetic mRNA is artificially created to study the translation process in protein synthesis. By using repeating sequences, such as the UG dinucleotide, researchers can predict the resulting polypeptide chain. This method allows scientists to observe how specific nucleotide sequences influence the formation of amino acid chains, thereby providing insights into the genetic code's structure.

Polypeptide Composition and Codon Recognition

The composition of the resulting polypeptide from the translation of synthetic mRNA provides evidence for the triplet nature of the genetic code. By analyzing the amino acids produced from a known sequence, researchers can confirm that each set of three nucleotides (codon) corresponds to a specific amino acid. This relationship between codons and amino acids is fundamental in validating the genetic code's triplet structure.