Table of contents

1. Introduction to Genetics51m
2. Mendel's Laws of Inheritance3h 37m
3. Extensions to Mendelian Inheritance2h 41m
4. Genetic Mapping and Linkage2h 28m
5. Genetics of Bacteria and Viruses1h 21m
6. Chromosomal Variation1h 48m
7. DNA and Chromosome Structure56m
8. DNA Replication1h 10m
9. Mitosis and Meiosis1h 34m
10. Transcription1h 0m
11. Translation58m
12. Gene Regulation in Prokaryotes1h 19m
13. Gene Regulation in Eukaryotes44m
14. Genetic Control of Development44m
15. Genomes and Genomics1h 50m
16. Transposable Elements47m
17. Mutation, Repair, and Recombination1h 6m
18. Molecular Genetic Tools19m
- Genetic Cloning
  9m
- Methods for Analyzing DNA
  9m
19. Cancer Genetics29m
- Overview of Cancer
  21m
- Cancer Mutations
  7m
20. Quantitative Genetics1h 26m
21. Population Genetics50m
- Hardy Weinberg
  19m
- Allelic Frequency Changes
  31m
22. Evolutionary Genetics29m

11. Translation

The Genetic Code

Genetics

11. Translation

The Genetic Code

Previous problemNext problem

2:43 minutes

Problem 24c

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

Verified step by step guidance

Understand the context: Har Gobind Khorana's experiments involved synthesizing mRNA molecules with specific repeating sequences to study how codons are translated into amino acids. The repeating UG dinucleotide sequence in this experiment is key to understanding the triplet nature of the genetic code.

Recognize the repeating UG sequence: The mRNA molecule consists of a repeating UG dinucleotide sequence, which can be represented as UGUGUGUG... This sequence is read by the ribosome in sets of three nucleotides (triplets) during translation.

Determine the possible codons: From the repeating UG sequence, the ribosome can form two distinct codons depending on the reading frame: UGU and GUG. These codons correspond to specific amino acids based on the genetic code.

Analyze the polypeptide composition: Translation of the mRNA results in a polypeptide composed of alternating amino acids, which correspond to the codons UGU and GUG. This alternating pattern confirms that the genetic code is read in triplets, as the sequence produces distinct amino acids depending on the reading frame.

Conclude the significance: The experiment demonstrated that the genetic code operates in a triplet manner, as the repeating UG sequence produced a predictable and consistent polypeptide composition based on the codons formed. This provided strong evidence for the triplet nature of the genetic code.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

Play a video:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

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 means that each set of three nucleotides in mRNA translates into one amino acid during protein synthesis. Understanding this concept is crucial for interpreting how sequences of nucleotides dictate the structure and function of proteins.

Synthetic mRNA and Translation

Synthetic mRNA is artificially created RNA that can be used in experiments to study translation and protein synthesis. By using a repeating sequence, such as UG, researchers can predict the resulting polypeptide chain. The translation of synthetic mRNA into proteins provides direct evidence of how codons are read and interpreted by the ribosome.

Polypeptide Composition and Codon Analysis

The composition of the resulting polypeptide from the translation of synthetic mRNA can reveal the specific amino acids produced, which in turn confirms the triplet nature of the genetic code. By analyzing the sequence of amino acids, scientists can deduce how many nucleotides correspond to each amino acid, thereby supporting the hypothesis that three nucleotides form a single codon.

Watch next

Master The Genetic Code with a bite sized video explanation from Kylia

Start learning

Related Videos

Related Practice

Textbook Question

The amino acid sequence of a portion of a polypeptide is

N...Cys-Pro-Ala-Met-Gly-His-Lys...C

Give the DNA template and coding strand sequences corresponding to the mRNA. Use the N, Pu, and Py symbols as placeholders.

627

views

Textbook Question

The amino acid sequence of a portion of a polypeptide is

N...Cys-Pro-Ala-Met-Gly-His-Lys...C

What is the mRNA sequence encoding this polypeptide fragment? Use N to represent any nucleotide, Pu to represent a purine, and Py to represent a pyrimidine. Label the 5′ and 3′ ends of the mRNA.

804

views

Textbook 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 overlapping rather than nonoverlapping, how would the result of this experiment be different?

641

views

Textbook Question

If the genetic code were a doublet code instead of a triplet code, how would the result of this experiment be different?

516

views

Textbook Question

What is the sequence of the resulting polypeptide?

483

views

Textbook Question

Write the sequence of this mRNA and give its polarity.

541

views

Textbook 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?

501

views

Textbook Question

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

What is the result obtained from each reading frame?

514

views

Show more practices

Download the Mobile app

Privacy

Do not sell my personal information

Accessibility

Patent notice

Sitemap

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

Synthetic mRNA and Translation

Polypeptide Composition and Codon Analysis

Watch next

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?