An experiment by Khorana and his colleagues translated a...

Question

An experiment by Khorana and his colleagues translated a synthetic mRNA containing repeats of the trinucelotide UUG.

How does the result of this experiment help confirm the triplet nature of the genetic code?

Accepted Answer

Welcome back, everyone. Here's our next question. Which of the following polypeptides will not be generated from a synthetic M R N A created by a researcher using trinucleotide repeats of U G U. And our answer choices are a repeated cystine units. So si si si si si dot dot dot Choice B, repeating veiling units. So Vow, vow, vow, vow, vow dot dot dot Choice C repeating lucine units. So li li li li li dot dot dot and choice D A repeating pattern of cystine bale lucine cystine ball lucine dot dot dot So we have trinucleotide repeats of U G U in our synthetic M R N A. So we envision that our strand is going to be U G U U G U U G U dot dot dot Well, we can read this in repeated units of U G U. So whichever amino acid that codes for, but we actually have three different possible reading frames for this strand. So if our reading frame starts with our base G, the second one here, our repeating units will be G U U G U U. So that would be a different code on and a different amino acid repeating over and over again. And finally, our third reading frame would be if we started with the third base of U. And then we had repeating units of U U G U U G dot dot dot So we'd have repeating units of the amino acid coded for by U U G. Well, we could now go and look up which amino acids those codons code for. However, we don't even need to go as far as a coat on table because we notice that no matter what the reading frame, it's going to be the same amino acid over and over again, we're looking for which polypeptide will not be generated. So that takes us to choice d the repeating pattern of cystine val lucine, cystine valley lucine because this would involve three different codons repeating. Whereas we know again, no matter what the reading frame, we have the same code on over and over again. And each codon codes for a single amino acid, you could have multiple codons that code for the same amino acid. But once you have a specific code on it only codes for one possibility. So it doesn't even matter which presumably one of these codones will be for cystine, one for vale and one for lucine. But since we only have to find the one that's not a possibility which of the following pop polypeptides will not be generated from a synthetic M R N A created by a researcher using trinucleotide repeats of U G U. That would be choice D Cystine valley lucine Cystine Valley lucine dot dot dot See you in the next video.

An experiment by Khorana and his colleagues translated a synthetic mRNA containing repeats of the trinucelotide UUG.

How does the result of this experiment help confirm the triplet nature of the genetic code?

Key Concepts

Triplet Nature of the Genetic Code

mRNA and Translation

Experimental Evidence in Genetics

Watch next

An experiment by Khorana and his colleagues translated a synthetic mRNA containing repeats of the trinucelotide UUG.How does the result of this experiment help confirm the triplet nature of the genetic code?

Key Concepts

Triplet Nature of the Genetic Code

mRNA and Translation

Experimental Evidence in Genetics

Watch next

An experiment by Khorana and his colleagues translated a synthetic mRNA containing repeats of the trinucelotide UUG.

How does the result of this experiment help confirm the triplet nature of the genetic code?