![Chemistry for Today: General, Organic, and Biochemistry](https://www.bartleby.com/isbn_cover_images/9781305960060/9781305960060_largeCoverImage.gif)
Concept explainers
Which of the following statements about the genetic code are true and which are false? Correct each false statement.
a. Each codon is composed of four bases.
b. Some amino acids are represented by more than one carbon.
c. All codons represent an amino acid.
d. Each living species is thought to have its own unique genetic code.
e. The codon AUG at the beginning of a sequence is a signal for protein synthesis to begin at that codon.
f. It is not known if the code contains stop signals for protein synthesis.
![Check Mark](/static/check-mark.png)
(a)
Interpretation:
The statement about genetic code that each codon is composed of four bases is true or false is to be predicted. The correct statement is to be stated.
Concept introduction:
The three nitrogenous bases present on messenger RNA which corresponds to specific amino acid are known as codon. The three nitrogenous bases present on transfer RNA which are complementary to three nitrogenous bases present on messenger RNA are known as anticodon.
Answer to Problem 21.40E
The statement about genetic code that each codon is composed of four bases is false. The correct statement is that each codon is composed for three bases.
Explanation of Solution
The three nitrogenous bases present on messenger RNA which corresponds to a specific amino acid are known as codon. Therefore, it is false that each codon is composed of four bases. The correct statement is that each codon is composed for three bases.
The statement about genetic code that each codon is composed of four bases is false. The correct statement is that each codon is composed for three bases.
![Check Mark](/static/check-mark.png)
(b)
Interpretation:
The statement about genetic code that some amino acids are represented by more than one codon is true or false is to be predicted. The correct statement is to be stated.
Concept introduction:
The three nitrogenous bases present on messenger RNA which corresponds to specific amino acid are known as codon. The three nitrogenous bases present on transfer RNA which are complementary to three nitrogenous bases present on messenger RNA are known as anticodon.
Answer to Problem 21.40E
The statement about genetic code that some amino acids are represented by more than one codon is true.
Explanation of Solution
The three nitrogenous bases present on messenger RNA which corresponds to a specific amino acid are known as codon. It is true that some amino acids are represented by more than one codon. For example, amino acid alanine is represented by four different codons GCA, GCC, GCG and GCU.
The statement about genetic code that some amino acids are represented by more than one codon is true.
![Check Mark](/static/check-mark.png)
(c)
Interpretation:
The statement about genetic code that all codons represent an amino acid is true or false is to be predicted. The correct statement is to be stated.
Concept introduction:
The three nitrogenous bases present on messenger RNA which corresponds to specific amino acid are known as codon. The three nitrogenous bases present on transfer RNA which are complementary to three nitrogenous bases present on messenger RNA are known as anticodon.
Answer to Problem 21.40E
The statement about genetic code that all codons represent an amino acid is false. Out of
Explanation of Solution
The three nitrogenous bases present on messenger RNA which corresponds to a specific amino acid are known as codon. However, codons UAG, UAA and UGA do not correspond to any amino acid. They represent a stop signal during the synthesis of protein.
The total number of codons is
The statement about genetic code that all codons represent an amino acid is false. Out of
![Check Mark](/static/check-mark.png)
(d)
Interpretation:
The statement about genetic code that each living species has its own unique genetic code is true or false is to be predicted. The correct statement is to be stated.
Concept introduction:
The three nitrogenous bases present on messenger RNA which corresponds to specific amino acid are known as codon. The three nitrogenous bases present on transfer RNA which are complementary to three nitrogenous bases present on messenger RNA are known as anticodon.
Answer to Problem 21.40E
The statement about genetic code that each living species has its own unique genetic code is false. The correct statement is that each living species contains same genetic codes but in a different sequence.
Explanation of Solution
The genetic codes present in each of the living species are the same; however, the arrangement of these genetic codes is different in each species. Therefore, the statement about genetic code that each living species has its own unique genetic code is false. The correct statement is that each living species contains same genetic codes but in a different sequence.
The statement about genetic code that each living species has its own unique genetic code is false. The correct statement is that each living species contains same genetic codes but in a different sequence.
![Check Mark](/static/check-mark.png)
(e)
Interpretation:
The statement about genetic code that codon AUG at the beginning of a sequence is a signal for protein synthesis to begin at that code is true or false is to be predicted. The correct statement is to be stated.
Concept introduction:
The three nitrogenous bases present on messenger RNA which corresponds to specific amino acid are known as codon. The three nitrogenous bases present on transfer RNA which are complementary to three nitrogenous bases present on messenger RNA are known as anticodon.
Answer to Problem 21.40E
The statement about genetic code that codon AUG at the beginning of a sequence is a signal for protein synthesis to begin at that code is true.
Explanation of Solution
The triplet code that represents the start of the signal during translation is AUG. Therefore, the statement about genetic code that codon AUG at the beginning of a sequence is a signal for protein synthesis to begin at that code is true.
The statement about genetic code that codon AUG at the beginning of a sequence is a signal for protein synthesis to begin at that code is true.
![Check Mark](/static/check-mark.png)
(f)
Interpretation:
The statement about genetic code that in a protein synthesis the code contains stop signals is not known is true or false is to be predicted. The correct statement is to be stated.
Concept introduction:
The three nitrogenous bases present on messenger RNA which corresponds to specific amino acid are known as codon. The three nitrogenous bases present on transfer RNA which are complementary to three nitrogenous bases present on messenger RNA are known as anticodon.
Answer to Problem 21.40E
The statement about genetic code that in a protein synthesis the code contains stop signals is not known is false. The correct statement is that three codons are represented as a stop signal in the protein synthesis.
Explanation of Solution
The triplet codes that correspond to the stop signals are UAG, UAA and UGA. If the code contains UAG, UAA or UGA, the synthesis of protein stops. Therefore, the statement about genetic code that in a protein synthesis the code contains stop signals is not known is false. The correct statement is that three codons are represented as a stop signal in the protein synthesis.
The statement about genetic code that in a protein synthesis the code contains stop signal is not known is false. The correct statement is that three codons are represented as a stop signal in the protein synthesis.
Want to see more full solutions like this?
Chapter 21 Solutions
Chemistry for Today: General, Organic, and Biochemistry
- If a codon consists of two nucleotides, how many codons would be possible? Would this be a workable code for the purpose of protein synthesis?arrow_forwarda Describe the three components of a nucleotide. b How does the structure of an RNA nucleotide differ from that of a DNA nucleotide?arrow_forwardIf a codon consists of four nucleotides, how many codons would be possible? Would this be workable as an amino-acid code?arrow_forward
- What are the dangers inherent in applying genetic engineering to human embryos? What are the benefits?arrow_forwardThe base sequences in mRNA that code for certain amino acids are Glu: GAA, GAG Val: GUU, GUC, GUA, GUG Met: AUG Trp: UGG Phe: UUU, UUC Asp: GAU, GAC These sequences are complementary to the sequences in DNA. a. Give the corresponding sequences in DNA for the amino acids listed above. b. Give a DNA sequence that would code for the peptide trp-glu-phe-met. c. How many different DNA sequences can code for the tetrapeptide in part b? d. What is the peptide that is produced from the DNA sequence TACCTGAAG? e. What other DNA sequences would yield the same tripeptide as in part d?arrow_forwardExplain why the base sequence ATC could not be a codon.arrow_forward
- Chemistry for Today: General, Organic, and Bioche...ChemistryISBN:9781305960060Author:Spencer L. Seager, Michael R. Slabaugh, Maren S. HansenPublisher:Cengage LearningChemistry: Matter and ChangeChemistryISBN:9780078746376Author:Dinah Zike, Laurel Dingrando, Nicholas Hainen, Cheryl WistromPublisher:Glencoe/McGraw-Hill School Pub CoChemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning
- Chemistry & Chemical ReactivityChemistryISBN:9781133949640Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage LearningChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage LearningChemistry: An Atoms First ApproachChemistryISBN:9781305079243Author:Steven S. Zumdahl, Susan A. ZumdahlPublisher:Cengage Learning
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305960060/9781305960060_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781337399074/9781337399074_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781133949640/9781133949640_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305957404/9781305957404_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305079243/9781305079243_smallCoverImage.gif)