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

2:31 minutes

Problem 15a

Textbook Question

Shown here is a hypothetical viral mRNA sequence:
5'-AUGCAUACCUAUGAGACCCUUGGA-3'
Assuming that it could arise from overlapping genes, how many different polypeptide sequences can be produced? What are the sequences?

Verified step by step guidance

Step 1: Understand the concept of overlapping genes. Overlapping genes occur when a single nucleotide sequence can be read in multiple reading frames, producing different polypeptides. This is possible because translation starts at different start codons (AUG) within the sequence.

Step 2: Identify all possible reading frames for the given mRNA sequence. There are three possible reading frames for a single strand of mRNA: Frame 1 starts at the first nucleotide, Frame 2 starts at the second nucleotide, and Frame 3 starts at the third nucleotide.

Step 3: For each reading frame, locate the start codon (AUG) and translate the sequence into amino acids until a stop codon (UAA, UAG, or UGA) is encountered. Use the genetic code table to determine the corresponding amino acids for each codon.

Step 4: Repeat the process for all three reading frames to identify all possible polypeptide sequences. Ensure that you account for overlapping regions where translation might start at different AUG codons within the same frame.

Step 5: Summarize the results by listing the number of distinct polypeptide sequences and their corresponding amino acid sequences for each reading frame. This will provide the final answer to the problem.

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.

Overlapping Genes

Overlapping genes occur when two or more genes share some of the same nucleotide sequences in their coding regions. This can lead to the production of multiple polypeptides from a single mRNA strand, as different reading frames can be utilized. Understanding how overlapping genes function is crucial for determining the potential diversity of protein products from a given mRNA sequence.

Reading Frames

A reading frame refers to the way nucleotides in an mRNA sequence are divided into codons, which are groups of three nucleotides that correspond to specific amino acids. There are three possible reading frames for any given mRNA sequence, depending on where translation begins. Identifying all possible reading frames is essential for predicting the different polypeptide sequences that can be generated from the same mRNA.

Polypeptide Sequences

Polypeptide sequences are chains of amino acids linked by peptide bonds, formed during the process of translation from mRNA. The sequence of amino acids determines the structure and function of the resulting protein. By analyzing the mRNA sequence and the different reading frames, one can deduce the various polypeptide sequences that can be synthesized, highlighting the complexity of gene expression.

Watch next

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

Start learning

Related Videos

Related Practice

Textbook Question

Third-base wobble allows some tRNAs to recognize more than one mRNA codon. Based on this chapter's discussion of wobble, what is the minimal number of tRNA molecules necessary to recognize the following amino acids?

Leucine

1072

views

Textbook Question

A short RNA molecule was isolated that demonstrated a hyperchromic shift, indicating secondary structure. Its sequence was determined to be

5'-AGGCGCCGACUCUACU-3'

If the molecule were an internal part of a message, what amino acid sequence would result from it following translation?

440

views

Textbook Question

A short RNA molecule was isolated that demonstrated a hyperchromic shift, indicating secondary structure. Its sequence was determined to be

5'-AGGCGCCGACUCUACU-3'

If the molecule were a tRNA fragment containing a CGA anticodon, what would the corresponding codon be?

493

views

Textbook Question

The genetic code contains 61 codons to specify the 20 common amino acids. Many organisms carry fewer than 61 different tRNA genes in their genomes. These genomes take advantage of isoaccepting tRNAs and the rules governing third-base wobble to encode fewer than 61 tRNA genes. Use these rules to calculate the minimal number of tRNA genes required to specify all 20 of the common amino acids.

571

views

Textbook Question

Most proteins have more leucine than histidine residues, but more histidine than tryptophan residues. Correlate the number of codons for these three amino acids with this information.

516

views

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 quadruplet with overlaps?

504

views

Textbook Question

A quadruplet without overlaps?

475

views

Textbook Question

A triplet with overlaps?

692

views

Show more practices