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

2:48 minutes

Problem 24e

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?

Verified step by step guidance

Understand the concept of overlapping versus nonoverlapping genetic code: In a nonoverlapping genetic code, each codon (group of three nucleotides) is read independently, without sharing nucleotides with adjacent codons. In an overlapping genetic code, each nucleotide could be part of multiple codons, meaning the reading frame shifts by one nucleotide for each new codon.

Analyze the synthetic mRNA sequence: The mRNA molecule in the experiment has a repeating UG dinucleotide sequence, which can be represented as UGUGUGUGUG... This sequence will be read in groups of three nucleotides (codons) during translation.

Consider the translation process in a nonoverlapping code: In a nonoverlapping genetic code, the codons would be read as UGUGUG... in groups of three, resulting in specific amino acids based on the genetic code table. Each codon is distinct and does not share nucleotides with adjacent codons.

Consider the translation process in an overlapping code: In an overlapping genetic code, the reading frame shifts by one nucleotide for each new codon. For example, the sequence UGUGUG... would produce codons like UGU, GUG, UGU, GUG... This would result in a different set of amino acids compared to the nonoverlapping code, as the codons are read differently.

Evaluate the experimental outcome: If the genetic code were overlapping, the amino acid sequence produced from the synthetic mRNA would differ significantly from the sequence produced under a nonoverlapping code. This is because the overlapping reading frame changes the codon composition and, consequently, the resulting amino acids.

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.

Genetic Code

The genetic code is a set of rules that defines how the sequence of nucleotides in mRNA is translated into amino acids, the building blocks of proteins. It consists of codons, which are triplets of nucleotides, each corresponding to a specific amino acid or a stop signal during protein synthesis.

Overlapping vs. Nonoverlapping Code

In a nonoverlapping genetic code, each nucleotide is part of only one codon, meaning that the reading frame shifts by three nucleotides for each new codon. In contrast, an overlapping code allows for shared nucleotides between adjacent codons, which can lead to different amino acid sequences being produced from the same mRNA sequence, significantly altering protein synthesis.

Translation of mRNA

Translation is the process by which ribosomes synthesize proteins using the information encoded in mRNA. During translation, the ribosome reads the mRNA sequence in codons, and tRNA molecules bring the corresponding amino acids to form a polypeptide chain. The structure of the genetic code directly influences the resulting protein's sequence and function.

Watch next

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

Start learning

Related Videos

Related Practice

Textbook Question

In an experiment to decipher the genetic code, a poly-AC mRNA (ACACACAC...) is synthesized. What pattern of amino acids would appear if this sequence were to be translated by a mechanism that reads the genetic code as

A doublet with overlaps?

592

views

Textbook Question

A doublet without overlaps?

479

views

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

516

views

Textbook Question

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

739

views

Textbook Question

What is the sequence of the resulting polypeptide?

483

views

Textbook Question