General, Organic & Biological Chemistry, 5e (Timberlake)
Chapter 21 Nucleic Acids and Protein Synthesis
21.1 Multiple-Choice Questions
1) A ________ consists of a nitrogen-containing a base and a sugar.
A) nucleoside
B) base pair
C) nucleotide
D) complementary base
E) pyrimidine
2) A ________ consists of a nitrogen-containing base, a sugar, and a phosphate group.
A) nucleoside
B) base pair
C) nucleotide
D) complementary base
E) purine
3) Which of the following can NOT be found in a nucleotide of RNA?
A) purine
B) pyrimidine
C) phosphate
D) ribose
E) deoxyribose
4) Which of the following is found in RNA but not in DNA?
A) thymine
B) uracil
C) guanine
D) cytosine
E) deoxyribose
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5) Which of the following will not be found in DNA?
A) adenine
B) thymine
C) guanine
D) cytosine
E) ribose
6) Which of the following can be found in DNA?
A) ribose
B) GMP
C) uracil
D) deoxyadenosine
E) FMN
7) Guanine is one example of a nitrogen base that is a
A) cofactor.
B) 5-carbon sugar.
C) phosphodiester.
D) pyrimidine.
E) purine.
8) The nucleotides in the backbone of DNA are held together by ________ bonds.
A) hydrogen
B) peptide
C) phosphodiester
D) glycosidic
E) ionic
9) The bonds that link the base pairs in the DNA double helix are
A) ionic bonds.
B) peptide bonds.
C) hydrogen bonds.
D) hydrophobic bonds.
E) ester bonds.
10) Which of the following hold two strands of DNA in an a helix?
A) ester linkages
B) disulfide linkages
C) peptide bonds
D) hydrogen bonds
E) glycosidic linkages
11) The base sequence of the strand of DNA complementary to the segment
5′ T-G-G-C-A-A-C 3′ is
A) 3′ T-G-G-C-A-A-C 5′.
B) 3′ A-C-C-G-T-T-G 5′.
C) 3′ A-C-C-G-U-U-G 5′.
D) 3′ U-C-C-G-T-T-G 5′.
E) 3′ A-C-G-C-T-U-G 5′.
12) When DNA duplicates itself, the correct placement of the nucleotides is accomplished by
A) complementary base pairing.
B) polymerase.
C) enzyme matching.
D) base matching.
E) transcription.
13) When DNA replicates, a guanine forms a base pair with
A) uracil.
B) adenine.
C) guanine.
D) thymine.
E) cytosine.
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14) Which one of the following base pairs is found in DNA?
A) adenine-thymine
B) adenine-guanine
C) cytosine-thymine
D) adenine-uracil
E) guanine-uracil
15) Which of the following statements is TRUE?
A) Cytosine and Thymine are a complementary base pair that forms 3 hydrogen bonds.
B) Thymine and Guanine are a complementary base pair that forms 3 hydrogen bonds.
C) Cytosine and Guanine are a complementary base pair that forms 2 hydrogen bonds.
D) Thymine and Adenine are a complementary base pair that forms 2 hydrogen bonds.
E) Thymine and Guanine are a complementary base pair that forms 2 hydrogen bonds.
16) The two strands of the double helix of DNA are held together by
A) hydrogen bonds.
B) covalent bonds.
C) dipole-dipole interactions.
D) ionic bonds.
E) sugar-to-phosphate bonds.
17) Which of the following is NOT a step in DNA replication?
A) mRNA sends a message to form a new strand of DNA.
B) A base on the DNA pairs with its complementary base free in solution.
C) DNA polymerase forms bonds between a 5′-phosphate of one nucleotide and a 3′-hydroxyl of another.
D) On one strand the DNA is synthesized continuously.
E) DNA ligase connects short segments of DNA on one strand.
18) The two new DNA molecules formed in replication
A) are complementary to the original DNA.
B) both contain only two new daughter DNA strands.
C) both contain only the parent DNA strands.
D) contain one parent and one daughter strand.
E) are identical, with one containing both parent strands, and the other containing both daughter strands.
19) What is the process in which the DNA double helix unfolds, and each strand serves as a template for
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the synthesis of a new strand?
A) transcription
B) complementation
C) translation
D) replication
E) restriction
20) The backbone of the helix of DNA is held together by
A) hydrogen bonds.
B) covalent bonds.
C) dipole-dipole interactions.
D) ionic bonds.
E) sugar-to-phosphate bonds.
21) Which of the following types of RNA carries the genetic information from DNA in the nucleus to the
cytoplasm for protein synthesis?
A) mRNA
B) histone RNA
C) rRNA
D) tRNA
E) sRNA
22) In transcription
A) the mRNA produced is identical to the parent DNA.
B) a double helix containing one parent strand and one daughter strand is produced.
C) uracil pairs with thymine.
D) both strands of the DNA are copied.
E) the mRNA produced is complementary to one strand of the DNA.
23) Which of the following is a section of mRNA produced from the DNA template below?
3′ A-T-A-G-C-T-A 5′
A) 5′ A-T-A-G-C-T-A 3′
B) 5′ A-U-A-G-C-U-A 3′
C) 5′ U-A-U-C-G-A-U 3′
D) 5′ U-U-U-G-C-U-U 3′
E) 5′ T-A-T-C-G-A-T 3′
24) Which of the following is a section of mRNA produced from the DNA template below?
3′ A-A-G-C-G-A-A 5′
A) 5′ A-T-A-G-C-T-A 3′
B) 5′ A-U-A-G-C-U-A 3′
C) 5′ U-A-U-C-G-A-U 3′
D) 5′ U-U-U-G-C-U-U 3′
E) 5′ T-A-T-C-G-A-T 3′
25) Which one of these base pairs is found in RNA?
A) guanine-cytosine
B) adenine-cytosine
C) adenine-thymine
D) adenine-guanine
E) guanine-thymine
26) In the synthesis of mRNA, an adenine in the DNA pairs with
A) uracil.
B) adenine.
C) guanine.
D) thymine.
E) cytosine.
27) A DNA template having the base sequence 3′ A-G-A-T-G-A 5′ would produce a mRNA with a base
sequence of
A) 5′ A-G-A-T-G-A 3′.
B) 5′ U-C-U-A-C-U 3′.
C) 5′ T-C-T-U-C-T 3′.
D) 5′ T-C-T-A-C-A 3‘.
E) 5′ A-C-A-U-C-A 3′.
28) When mRNA is synthesized using the information from DNA, the process is called
A) transportation.
B) transposition.
C) transcription.
D) translation.
E) transliteration.
29) The anticodon is
A) identical to the codon on DNA.
B) complementary to the codon on DNA.
C) identical to the codon on mRNA.
D) complementary to the codon on mRNA.
E) complementary to the codon on tRNA.
30) A set of directions in the DNA base sequence for the synthesis of a protein is a(n)
A) structural gene.
B) promotor.
C) operator.
D) codon.
E) regulatory gene.
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31) Which of the following types of RNA has a large subunit and a small subunit?
A) mRNA
B) histone RNA
C) rRNA
D) tRNA
E) sRNA
32) Some sections of a DNA molecule do not code for protein synthesis. These segments are called
A) codons.
B) anticodons.
C) Okazaki fragments.
D) introns.
E) exons.
33) Codons are base pair sequences that
A) signal the start of DNA synthesis.
B) signal the end of DNA synthesis.
C) code for amino acids.
D) signal the start of RNA synthesis.
E) code for one or more bases in mRNA.
34) The codon is found on ________, and the anticodon is found on ________.
A) mRNA; tRNA
B) tRNA; mRNA
C) rRNA; tRNA
D) ribosomes; tRNA
E) mRNA; rRNA
35) Translation is the process whereby
A) DNA is synthesized from DNA.
B) DNA is synthesized from mRNA.
C) protein is synthesized from DNA.
D) protein is synthesized from mRNA.
E) mRNA is synthesized from DNA.
36) Which of the following is not a step in protein synthesis?
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A) activation of tRNA
B) initiation
C) elongation
D) termination
E) unwinding of two strands of mRNA
37) A tRNA is activated when it
A) attaches to mRNA.
B) attaches to its specific amino acid.
C) attaches to the ribosome.
D) leaves the ribosome.
E) releases its specific amino acid.
38) During protein synthesis, the codon for an amino acid is found on
A) DNA.
B) rRNA.
C) tRNA.
D) mRNA.
E) sRNA.
39) The anticodon of U-A-G is
A) A-T-C.
B) U-A-G.
C) A-A-C.
D) A-U-C.
E) G-A-U.
40) Mutations are the result of
A) alterations in the phosphate of the DNA backbone.
B) exposure to water in utero.
C) physical trauma in the mother’s childhood.
D) alterations in the sugar component of the DNA backbone.
E) alterations in the DNA base sequence.
41) The result of a defective enzyme caused by a mutation in the DNA nucleotide sequence is
A) a genetic disease.
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B) AIDS.
C) HIV.
D) recombinant DNA.
E) translocation.
42) When a mutation occurs by elimination of one base in a DNA sequence, this mutation is called a
A) deletion mutation.
B) retrovirus insertion.
C) substitution mutation.
D) translocation mutation.
E) viral mutation.
43) In the study of genetics, the abbreviation PCR refers to
A) purine chain repression.
B) pyrimidine complement restriction.
C) purine coded ribose.
D) protein combination and replication.
E) polymerase chain reaction.
44) Recombinant DNA technology requires the use of bacterial
A) plasmids.
B) mitochondria.
C) endoplasmic reticulum.
D) ribosomes.
E) cell walls.
45) One therapeutic product now available due to recombinant DNA technology is
A) measles vaccine.
B) penicillin.
C) human growth hormone.
D) sulfamethoxazole.
E) tamoxifen.
46) DNA fingerprinting uses ________ to produce DNA fragments that can be separated and screened for
the presence of genetic diseases.
A) extracellular DNA
B) restriction enzymes
C) bacterial plasmids
D) anticodons
E) codons
47) The purpose of the human genome project was to
A) identify genes responsible for noninheritable diseases.
B) determine how to clone human DNA.
C) identify substrates for the polymerase chain reaction.
D) learn how to clone bacterial DNA.
E) map the locations of all the genes in human DNA.
48) Which of the following is used in the preparation of recombinant DNA?
A) RNA polymerase
B) DNA polymerase
C) repressor protein
D) restriction enzyme
E) enzyme induction
49) The insertion of new DNA into the plasmid DNA of a bacterium produces
A) viral DNA.
B) DNA fingerprints.
C) recombinant DNA.
D) ribosomes.
E) restriction enzymes.
50) The polymerase chain reaction is used in
A) preparing recombinant DNA.
B) transcription.
C) DNA fingerprinting.
D) translation.
E) replication.
51) A restriction enzyme functions to
A) prevent the DNA from leaving the nucleus.
B) limit the number of replications a DNA molecule can achieve.
C) cut a large DNA double helix into smaller fragments.
D) stop the elongation step of protein synthesis.
E) eliminate a virus from a cell.
52) Small living particles, with 3 to 200 genes, that cannot replicate without a host cell are called
A) recombinant DNAs.
B) viruses.
C) bacteria.
D) tumors.
E) plasmids.
53) A virus that contains RNA as its genetic material is a
A) genetically engineered virus.
B) bacteria.
C) recombinant DNA.
D) retrovirus.
E) vaccine.
54) Protease inhibitors, which are effective anti-HIV drugs,
A) are nucleoside analogs.
B) prevent reverse transcription.
C) prevent synthesis of viral proteins.
D) prevent mRNA synthesis.
E) prevent activation of tRNA.
21.2 True/False Questions
1) Adenine is a purine.
2) Uracil is a pyrimidine.
3) DNA is a protein.
4) A nucleotide consists of only a base and a sugar.
5) DNA differs from RNA in the sugar it contains.
6) The sequence of bases in a nucleic acid is the primary structure.
7) The backbone of a nucleic acid is the nitrogen bases.
8) In the DNA double helix, a purine can only bond with a pyrimidine.
9) If the DNA double helix in humans contains 20% guanine, then the percent cytosine is 30%.
10) If the DNA double helix in humans contains 20% guanine, then the percent adenine is 30%.
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11) If the DNA double helix in humans contains 20% guanine, then the percent cytosine is 20%.
12) Okazaki fragments are short segments formed by DNA polymerase in the daughter DNA strand that
runs in the 3′ to 5′ direction.
13) The DNA complement of the sequence 5′ G-C-C-A-T 3‘ is 3 -G-C-C-A-T 5′.
14) The enzyme helicase seperartes the two DNA strands.
15) RNA contains no phosphate.
16) Human DNA contains many nucleotides that are not used in genes.
17) Messenger RNA carries protein synthesis information from the nucleus to the ribosomes.
18) mRNA is the smallest type of RNA.
19) The anticodon sequence is found in mRNA.
20) The mRNA triplet UUU codes for phenylalanine.
21) Down syndrome is an acquired disease, not a genetic disease.
22) Human insulin can be made with the use of recombinant DNA technology.
23) DNA fingerprinting is not yet used to detect genes for cancer susceptibility.
24) A retrovirus uses DNA as its genetic material.
25) AZT is a drug used in the treatment of colds.
26) A retrovirus contains DNA as its genetic material and that synthesizes a complementary RNA strand
inside a cell.
21.3 Matching Questions
Match the following.
A) mRNA
B) DNA
C) tRNA
D) rRNA
1) picks up the specific amino acids for protein synthesis
Objective: 21.5
Global Outcomes: GO2
2) synthesized by the DNA to carry the genetic message to the ribosomes
Objective: 21.5
Global Outcomes: GO2
3) contains within the nucleus of the cell the information for the synthesis of protein
Objective: 21.5
Global Outcomes: GO2
4) the nucleic acid that contains the codons for the amino acids of a protein
Objective: 21.5
Global Outcomes: GO2
5) the most abundant nucleic acid in the ribosomes
Objective: 21.5
Global Outcomes: GO2
6) the nucleic acid that contains a single anticodon for a specific amino acid
Objective: 21.5
Global Outcomes: GO2
Match the correct term with the statement.
A) transcription factor
B) operon
C) activators
D) repressor
E) promoter
7) the protein complexes that bind to the promoter region of DNA
Objective: 21.5
Global Outcomes: GO2
8) a group of genes whose transcription is controlled by the same regulatory gene
Objective: 21.5
Global Outcomes: GO2
9) the portion of the control site that regulates DNA synthesis
Objective: 21.5
Global Outcomes: GO2
10) a protein that interacts with the operator gene to prevent mRNA synthesis
Objective: 21.5
Global Outcomes: GO2
11) proteins that bind to transcription factors to increase the transcription rate
Objective: 21.5
Global Outcomes: GO2