Question 1

Which of the following best explains why the ratios of A/T and G/C are 0.77 and 1.08, respectively in bacteriophage $\varPhi$X174?

Accepted Answer

A) the base pairing in bacteriophages is not always A-T and C-G 
B) studies done with most bacteriophages do not use complete genomic DNA due to the inherent instability of phage DNA 
C) bacteriophage DNA often uses bases other than A, T, C and G 
D) many viruses often use single stranded DNA 
E) none of the above 
A) the base pairing in bacteriophages is not always A-T and C-G 
B) studies done with most bacteriophages do not use complete genomic DNA due to the inherent instability of phage DNA 
C) bacteriophage DNA often uses bases other than A, T, C and G 
D) many viruses often use single stranded DNA 
E) none of the above D

Question 2

Which of the following is correctly paired with the type of tautomerization(s)that occurs?

Accepted Answer

A) adenine: keto-enol 
B) cytosine: amino-imino and keto-enol 
C) guanine: amino-imino 
D) thymine: keto-enol 
E) none of the above 
A) adenine: keto-enol 
B) cytosine: amino-imino and keto-enol 
C) guanine: amino-imino 
D) thymine: keto-enol 
E) none of the above D

Question 3

Which of the following is correct regarding the flow of genetic information?

Accepted Answer

A) replication uses a DNA template to form RNA which serves as the new template for DNA synthesis 
B) transcription produces RNA from a DNA template using the enzyme RNA polymerase 
C) translation uses mRNA as a template, rRNA to carry amino acids, and tRNA to catalyze the synthesis of proteins 
D) during both replication and transcription, the products are double stranded polynucleotides 
E) none of the above 
A) replication uses a DNA template to form RNA which serves as the new template for DNA synthesis 
B) transcription produces RNA from a DNA template using the enzyme RNA polymerase 
C) translation uses mRNA as a template, rRNA to carry amino acids, and tRNA to catalyze the synthesis of proteins 
D) during both replication and transcription, the products are double stranded polynucleotides 
E) none of the above B

Question 4

Based on the following, what can be said about the synthesis of polynucleotides?

Accepted Answer

A) polynucleotides are unstable and are rapidly degraded 
B) polynucleotide formation is made much more exergonic by the hydrolysis of pyrophosphate 
C) the hydrolysis of nucleoside triphosphates is the only driving force to make an overall irreversible reaction 
D) polynucleotides are highly resistant to hydrolysis, even in the presence of an acid catalyst 
E) none of the above 
A) polynucleotides are unstable and are rapidly degraded 
B) polynucleotide formation is made much more exergonic by the hydrolysis of pyrophosphate 
C) the hydrolysis of nucleoside triphosphates is the only driving force to make an overall irreversible reaction 
D) polynucleotides are highly resistant to hydrolysis, even in the presence of an acid catalyst 
E) none of the above

Question 5

Which of the following, when paired with its complementary strand, would have the highest Tm?

Accepted Answer

A) AAGTTCCAGT 
B) GCAGCAGCAT 
C) ATTACGAGCT 
D) GCGAAATCAA 
E) TGACCTTGAA 
A) AAGTTCCAGT 
B) GCAGCAGCAT 
C) ATTACGAGCT 
D) GCGAAATCAA 
E) TGACCTTGAA

Question 6

Where are G-quadruplexes most commonly found?

Accepted Answer

A) transcription termination sites 
B) origin of replication 
C) the ends of hairpin loops 
D) telomeres 
E) none of the above 
A) transcription termination sites 
B) origin of replication 
C) the ends of hairpin loops 
D) telomeres 
E) none of the above

Question 7

Which of the following is a major difference between B-DNA and A-DNA?

Accepted Answer

A) B-DNA has a right-handed helix, A-DNA has a left-handed helix 
B) B-DNA has 10 residues per helix turn while A-DNA has 9 
C) B-DNA base pairs are stacked almost parallel to one another while A-DNA base pairs are significantly tilted with respect to each other 
D) the major groove of A-DNA is much larger than that in B-DNA 
E) none of the above 
A) B-DNA has a right-handed helix, A-DNA has a left-handed helix 
B) B-DNA has 10 residues per helix turn while A-DNA has 9 
C) B-DNA base pairs are stacked almost parallel to one another while A-DNA base pairs are significantly tilted with respect to each other 
D) the major groove of A-DNA is much larger than that in B-DNA 
E) none of the above

Question 8

The following shows deoxyadenosine in the _____ conformation

Accepted Answer

A) syn 
B) anti 
C) cis 
D) trans 
E) none of the above 
A) syn 
B) anti 
C) cis 
D) trans 
E) none of the above

Question 9

Based on the following, which is true regarding the acid/base properties of guanine?

Accepted Answer

A) at physiological pH, guanine will be positively charged 
B) at physiological pH, guanine will be negatively charged 
C) at physiological pH, guanine will be neutral 
D) at physiological pH, guanine will be a very effective buffer against base 
E) at physiological pH, guanine will be a very effective buffer against acid 
A) at physiological pH, guanine will be positively charged 
B) at physiological pH, guanine will be negatively charged 
C) at physiological pH, guanine will be neutral 
D) at physiological pH, guanine will be a very effective buffer against base 
E) at physiological pH, guanine will be a very effective buffer against acid

Question 10

While RNA is often single stranded, transfer RNA (tRNA)is usually found with some double stranded structure. Which of the following explains this?

Accepted Answer

A) tRNAs contain self-complimentary stem-loop structures 
B) after synthesis, tRNA molecules are hydrolyzed in specific places to allow double stranded structures to form 
C) regions of tRNAs become supercoiled, thus forcing formation of double stranded regions 
D) tRNAs adopt a form much like Z-DNA allowing double stranded regions to form 
E) none of the above 
A) tRNAs contain self-complimentary stem-loop structures 
B) after synthesis, tRNA molecules are hydrolyzed in specific places to allow double stranded structures to form 
C) regions of tRNAs become supercoiled, thus forcing formation of double stranded regions 
D) tRNAs adopt a form much like Z-DNA allowing double stranded regions to form 
E) none of the above

Question 11

Which of the following bases is found only in DNA?

Accepted Answer

A) adenine 
B) thymine 
C) uracil 
D) cytosine 
E) guanine 
A) adenine 
B) thymine 
C) uracil 
D) cytosine 
E) guanine

Question 12

In a circular DNA molecule of 126 bp with 10.5 bp/turn, which of the following represents an unstrained circle? (L = linking number, T = twist and W = writhe)

Accepted Answer

A) L = 12, T = 12, W = 0 
B) L = 11, T = 11, W = 0 
C) L = 11, T = 12, W = -1 
D) L = 12, T = 11, W = +1 
E) L = 11, T = 10, W = 0 
A) L = 12, T = 12, W = 0 
B) L = 11, T = 11, W = 0 
C) L = 11, T = 12, W = -1 
D) L = 12, T = 11, W = +1 
E) L = 11, T = 10, W = 0

Question 13

Base stacking, or the "stacking interaction," is most likely the result of which noncovalent interaction

Accepted Answer

A) charge-dipole interaction 
B) dipole-dipole interaction 
C) dipole-induced dipole interaction 
D) van der Waals interaction 
E) none of the above 
A) charge-dipole interaction 
B) dipole-dipole interaction 
C) dipole-induced dipole interaction 
D) van der Waals interaction 
E) none of the above

Question 14

In the Watson-Crick DNA model, how many base pairs are found in one turn of the helix?

Accepted Answer

A) 4 
B) 6 
C) 8 
D) 10 
E) 12 
A) 4 
B) 6 
C) 8 
D) 10 
E) 12

Question 15

Which of the following is correctly paired?

Accepted Answer

A) adenine: pyrimidine 
B) RNA: ribose containing nucleic acid 
C) thymine: purine 
D) uracil: purine 
E) DNA: ribose containing nucleic acid 
A) adenine: pyrimidine 
B) RNA: ribose containing nucleic acid 
C) thymine: purine 
D) uracil: purine 
E) DNA: ribose containing nucleic acid

Question 16

Which of the following describes the directionality seen in nucleic acids?

Accepted Answer

A) most polynucleotides have an unreacted 5' hydroxyl group 
B) all polynucleotides have an unreacted 2' hydroxyl group 
C) most polynucleotides have a phosphate group on the 5'end 
D) sequences of polynucleotides are generally written from 3' on the left to 5' on the right 
E) none of the above 
A) most polynucleotides have an unreacted 5' hydroxyl group 
B) all polynucleotides have an unreacted 2' hydroxyl group 
C) most polynucleotides have a phosphate group on the 5'end 
D) sequences of polynucleotides are generally written from 3' on the left to 5' on the right 
E) none of the above

Question 17

Which of the following techniques was used to determine the double helical structure of DNA?

Accepted Answer

A) NMR spectroscopy 
B) X-ray diffraction 
C) Raman spectroscopy 
D) UV/Vis spectroscopy 
E) IR spectroscopy 
A) NMR spectroscopy 
B) X-ray diffraction 
C) Raman spectroscopy 
D) UV/Vis spectroscopy 
E) IR spectroscopy

Question 18

Which of the following types of DNA are often supercoiled?

Accepted Answer

A) extremely long linear DNA, such as seen in human chromosomes 
B) very short linear DNA 
C) circular DNA 
D) DNA molecules that contain both circular and linear regions 
E) all of the above 
A) extremely long linear DNA, such as seen in human chromosomes 
B) very short linear DNA 
C) circular DNA 
D) DNA molecules that contain both circular and linear regions 
E) all of the above

Question 19

Draw the structure of cytosine and thymine, then show the most common tautomer of each.

Accepted Answer

The answer of Draw the structure of cytosine and thymine,...

Question 20

Replication of DNA is best considered __________.

Accepted Answer

A) conservative 
B) semiconservative 
C) dispersive 
D) complementary 
E) none of the above 
A) conservative 
B) semiconservative 
C) dispersive 
D) complementary 
E) none of the above

Exam 4: Nucleic Acids

Which of the following best explains why the ratios of A/T and G/C are 0.77 and 1.08, respectively in bacteriophage Φ\varPhiΦ X174?

Which of the following is correctly paired with the type of tautomerization(s)that occurs?

Which of the following is correct regarding the flow of genetic information?

Based on the following, what can be said about the synthesis of polynucleotides?

Which of the following, when paired with its complementary strand, would have the highest Tm?

Where are G-quadruplexes most commonly found?

Which of the following is a major difference between B-DNA and A-DNA?

The following shows deoxyadenosine in the _____ conformation

Based on the following, which is true regarding the acid/base properties of guanine?

While RNA is often single stranded, transfer RNA (tRNA)is usually found with some double stranded structure. Which of the following explains this?

Which of the following bases is found only in DNA?

In a circular DNA molecule of 126 bp with 10.5 bp/turn, which of the following represents an unstrained circle? (L = linking number, T = twist and W = writhe)

Base stacking, or the "stacking interaction," is most likely the result of which noncovalent interaction

In the Watson-Crick DNA model, how many base pairs are found in one turn of the helix?

Which of the following is correctly paired?

Which of the following describes the directionality seen in nucleic acids?

Which of the following techniques was used to determine the double helical structure of DNA?

Which of the following types of DNA are often supercoiled?

Draw the structure of cytosine and thymine, then show the most common tautomer of each.

Replication of DNA is best considered __________.

The Scope of Biochemistry

The Matrix of Life: Weak Interactions in an Aqueous Environment

The Energetics of Life

Introduction to Proteins: the Primary Level of Protein Structure

The Three-Dimensional Structure of Proteins

Protein Function and Evolution

Contractile Proteins and Molecular Motors

Carbohydrates: Sugars, Saccharides, Glycans

Lipids, Membranes and Cellular Transport

Enzymes: Biological Catalysts

Chemical Logic of Metabolism

Carbohydrate Metabolism: Glycolysis, Gluconeogenesis, Glycogen Metabolism, and the Pentose Phosphate Pathway

Citric Acid Cycle and Glyoxylate Cycle

Electron Transport, Oxidative Phosphorylation, and Oxygen Metabolism

Photosynthesis

Lipid Metabolism I: Fatty Acids, Triacylglycerols, and Lipoproteins

Interorgan and Intracellular Coordination of Energy Metabolism in Vertebrates

Lipid Metabolism Ii: Membrane Lipids, Steroids, Isoprenoids, and Eicosanoids

Metabolism of Nitrogenous Compounds I: Principles of Biosynthesis, Utilization, and Turnover

Metabolism of Nitogenous Compounds II: Amino Acids, Porphyrins, and Neurotransmitters

Nucleotide Metabolism

Mechanisms of Signal Transduction

Genes, Genomes and Chromosomes

DNA Replication

DNA Restructuring: Repair, Recombination, Rearrangement, Amplification

Information Readout: Transcription and Post-Transcriptional Processing

Information Decoding: Translation and Post-Translational Protein Processing

Regulation of Gene Expression

Filters

Which of the following best explains why the ratios of A/T and G/C are 0.77 and 1.08, respectively in bacteriophage $\varPhi$ X174?

Which of the following, when paired with its complementary strand, would have the highest T_m?