Textbook Question
Consider the following segment of mRNA produced by the normal order of DNA nucleotides:
ACA UCA CGG GUA
a. What is the amino acid order produced from this mRNA?
Ch.17 Nucleic Acids and Protein Synthesis
Timberlake13th EditionChemistry: An Introduction to General, Organic, and Biological ChemistryISBN: 9780134421353
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Table of contents
- Ch.1 Chemistry in Our Lives11
- Ch.2 Chemistry and Measurements80
- Ch.3 Matter and Energy54
- Ch.4 Atoms and Elements51
- Ch.5 Nuclear Chemistry42
- Ch.6 Ionic and Molecular Compounds57
- Ch.7 Chemical Quantities and Reactions41
- Ch.8 Gases29
- Ch.9 Solutions51
- Ch.10 Acids and Bases and Equilibrium65
- Ch.11 Introduction to Organic Chemistry: Hydrocarbons78
- Ch.12 Alcohols, Thiols, Ethers, Aldehydes, and Ketones83
- Ch.13 Carbohydrates54
- Ch.14 Carboxylic Acids, Esters, Amines, and Amides90
- Ch.15 Lipids61
- Ch.16 Amino Acids, Proteins, and Enzymes84
- Ch.17 Nucleic Acids and Protein Synthesis83
- Ch.18 Metabolic Pathways and ATP Production67
Timberlake13th EditionChemistry: An Introduction to General, Organic, and Biological ChemistryISBN: 9780134421353Not the one you use?Change textbook
Chapter 17, Problem 65f
Consider the following segment of mRNA produced by the normal order of DNA nucleotides:
ACA UCA CGG GUA
f. What is the amino acid order if a deletion mutation removes the A at the beginning of the mRNA segment?
Verified step by step guidance1
Understand the problem: A deletion mutation removes the first nucleotide (A) from the mRNA sequence. This will cause a frameshift mutation, altering the reading frame of the codons. The task is to determine the new amino acid sequence after this mutation.
Write down the original mRNA sequence: ACA UCA CGG GUA. Codons are read in groups of three nucleotides, starting from the beginning.
Apply the deletion mutation: Remove the first nucleotide (A) from the sequence. The new mRNA sequence becomes CAU CAC GGG UA.
Reorganize the sequence into new codons based on the frameshift: The new codons are CAU, CAC, GGG, and UA (note that the last codon is incomplete and may not code for an amino acid).
Use the genetic code table to translate the new codons into their corresponding amino acids: Look up each codon (CAU, CAC, GGG) in the genetic code table to determine the new amino acid sequence. Ignore the incomplete codon (UA) as it does not form a valid triplet.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
mRNA and Codons
mRNA, or messenger RNA, is a single-stranded molecule that carries genetic information from DNA to the ribosome, where proteins are synthesized. It is composed of codons, which are sequences of three nucleotides that correspond to specific amino acids. Understanding how codons are formed and read is essential for determining the resulting amino acid sequence.
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6:37
Transcription: mRNA Synthesis Concept 1
Deletion Mutation
A deletion mutation occurs when one or more nucleotides are removed from the DNA sequence, which can lead to a shift in the reading frame of the mRNA. This shift can alter the entire sequence of amino acids produced during translation, potentially resulting in a nonfunctional protein. Recognizing the impact of such mutations is crucial for predicting changes in protein synthesis.
Amino Acid Sequence
The amino acid sequence is the order of amino acids in a protein, determined by the sequence of codons in the mRNA. Each amino acid is specified by a particular codon, and changes in the mRNA sequence, such as those caused by mutations, can lead to different amino acids being incorporated into the protein. This sequence ultimately dictates the protein's structure and function.
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3:03Amino Acid Catabolism: Amino Group Example 2
Related Practice
Textbook Question
Consider the following segment of mRNA produced by the normal order of DNA nucleotides:
ACA UCA CGG GUA
b. What is the amino acid order if a point mutation changes UCA to ACA?
Textbook Question
Consider the following segment of mRNA produced by the normal order of DNA nucleotides:
ACA UCA CGG GUA
e. What is the amino acid order if an insertion mutation adds a G to the beginning of the mRNA segment?
Textbook Question
A point mutation changes a codon in the mRNA for an enzyme from GCC to GCA. Why is there no change in the amino acid order in the protein?
Textbook Question
In sickle-cell anemia, a point mutation in the mRNA for hemoglobin results in the replacement of glutamate with valine in the resulting hemoglobin molecule. Why does the replacement of one amino acid cause such a drastic change in biological function?
Textbook Question
A point mutation in the mRNA for an enzyme results in the replacement of leucine with alanine in the resulting enzyme molecule. Why does this change in amino acids have little effect on the biological activity of the enzyme?