Question 1

Which of the following statements concerning small nuclear RNA is true?

Accepted Answer

A)  This RNA is usually found in snurps. 
B)  This RNA is involved in removing exons from the RNA. 
C)  This RNA was the first RNA shown to have catalytic activity. 
D)  This RNA is small in size. 
E)  All of these describe small nuclear RNA. 
A)  This RNA is usually found in snurps. 
B)  This RNA is involved in removing exons from the RNA. 
C)  This RNA was the first RNA shown to have catalytic activity. 
D)  This RNA is small in size. 
E)  All of these describe small nuclear RNA. E

Question 2

Calculate the length/diameter ratio for the extended E. coli DNA (4 Å between adjacent nucleotides). E. coli DNA has 2 × 106 bp.

Accepted Answer

A)  4 × 105 
B)  1 × 105 
C)  3 × 108 
D)  3 × 106 
A)  4 × 105 
B)  1 × 105 
C)  3 × 108 
D)  3 × 106 A

Question 3

Eukaryotic and prokaryotic ribosomes can be compared in all these ways, except:

Accepted Answer

A)  Both have large and small subunits. 
B)  Eukaryotic ribosomes are larger. 
C)  Both contain the same number of RNA molecules. 
D)  Eukaryotic ribosomes contain more proteins. 
E)  All of these statements are accurate comparisons. 
A)  Both have large and small subunits. 
B)  Eukaryotic ribosomes are larger. 
C)  Both contain the same number of RNA molecules. 
D)  Eukaryotic ribosomes contain more proteins. 
E)  All of these statements are accurate comparisons. C

Question 4

In a melting profile for DNA, the absorbance at 260 nm increases as result of the disruption of the DNA structure. What is the fundamental physical basis for the absorbance increase?

Accepted Answer

A)  the effective concentration of DNA changes 
B)  denatured DNA absorbs light more strongly than native DNA because the bases have become unstacked 
C)  native DNA absorbs light more strongly than denatured DNA because the bases are stacked 
D)  the absorbance of DNA is highly sensitive to temperature 
A)  the effective concentration of DNA changes 
B)  denatured DNA absorbs light more strongly than native DNA because the bases have become unstacked 
C)  native DNA absorbs light more strongly than denatured DNA because the bases are stacked 
D)  the absorbance of DNA is highly sensitive to temperature

Question 5

Which of the following is the most common modification of nucleic acid bases?

Accepted Answer

A)  addition of a methyl group 
B)  addition of a carboxylic acid 
C)  addition of a fluorine 
D)  reduction of a carbonyl to an alcohol 
A)  addition of a methyl group 
B)  addition of a carboxylic acid 
C)  addition of a fluorine 
D)  reduction of a carbonyl to an alcohol

Question 6

Which of the following nucleobases is a purine?

Accepted Answer

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

Question 7

The hydrogen bonding interactions in a Watson-Crick AT base-pair involve what units in the adenine base?

Accepted Answer

A)  N-1 and the amino group on C-6 
B)  N-1 and N-3 
C)  N-7 and the amino group on C-6 
D)  N-7 and C-8 
A)  N-1 and the amino group on C-6 
B)  N-1 and N-3 
C)  N-7 and the amino group on C-6 
D)  N-7 and C-8

Question 8

Supercoiling of DNA

Accepted Answer

A)  is not observed in prokaryotes 
B)  requires the action of topoisomerase enzymes 
C)  does not require ATP 
D)  is not observed in eukaryotes 
A)  is not observed in prokaryotes 
B)  requires the action of topoisomerase enzymes 
C)  does not require ATP 
D)  is not observed in eukaryotes

Question 9

Which of the following groups is not found in nucleosides?

Accepted Answer

A)  Phosphates 
B)  Purines 
C)  Pyrimidines 
D)  Sugars 
E)  All of these are found in nucleosides 
A)  Phosphates 
B)  Purines 
C)  Pyrimidines 
D)  Sugars 
E)  All of these are found in nucleosides

Question 10

In DNA structure, hydrophobic bonding via pi-clouds is referred to as

Accepted Answer

A)  base stacking. 
B)  propeller twist. 
C)  hyperchromicity. 
D)  supercoiling. 
E)  denaturation 
A)  base stacking. 
B)  propeller twist. 
C)  hyperchromicity. 
D)  supercoiling. 
E)  denaturation

Question 11

Which of the following can be an epigenetic change to chromatin?

Accepted Answer

A)  methylation 
B)  acetylation 
C)  phosphorylation 
D)  All of these 
E)  None of these 
A)  methylation 
B)  acetylation 
C)  phosphorylation 
D)  All of these 
E)  None of these

Question 12

The strands in the double helix

Accepted Answer

A)  both run in the same 3' → 5' direction, i.e., they are parallel. 
B)  have their 3' → 5' directions opposed, i.e., they are anti-parallel. 
C)  can be either parallel or anti-parallel. 
D)  are perpendicular to one another. 
E)  None of these 
A)  both run in the same 3' → 5' direction, i.e., they are parallel. 
B)  have their 3' → 5' directions opposed, i.e., they are anti-parallel. 
C)  can be either parallel or anti-parallel. 
D)  are perpendicular to one another. 
E)  None of these

Question 13

The double helix of DNA is which level of structure?

Accepted Answer

A)  primary 
B)  secondary 
C)  tertiary 
D)  quaternary 
E)  None of these 
A)  primary 
B)  secondary 
C)  tertiary 
D)  quaternary 
E)  None of these

Question 14

Which contains a phosphoanhydride bond?

Accepted Answer

A)  DNA 
B)  RNA 
C)  ATP 
D)  AMP 
E)  None of these 
A)  DNA 
B)  RNA 
C)  ATP 
D)  AMP 
E)  None of these

Question 15

Which of the following characteristics is associated with the B form of DNA?

Accepted Answer

A)  the sugars are located in the interior of the double helix 
B)  the distance between base pairs along the axis of the helix is 8 Å 
C)  the major and minor grooves are readily apparent 
D)  the planes of the bases make about a 20 degree angle with the helix axis 
A)  the sugars are located in the interior of the double helix 
B)  the distance between base pairs along the axis of the helix is 8 Å 
C)  the major and minor grooves are readily apparent 
D)  the planes of the bases make about a 20 degree angle with the helix axis

Question 16

The Tm for melting the double helix is:

Accepted Answer

A)  The temperature at which the helix starts to open. 
B)  The midpoint of the range over which the helix denatures. 
C)  The temperature at which the helix is completely open. 
D)  The energy needed to melt the DNA. 
E)  None of these is correct. 
A)  The temperature at which the helix starts to open. 
B)  The midpoint of the range over which the helix denatures. 
C)  The temperature at which the helix is completely open. 
D)  The energy needed to melt the DNA. 
E)  None of these is correct.

Question 17

The oligonucleotide AGGUCCAUUGAAp, is best described as

Accepted Answer

A)  an RNA oligonucleotide with a 3'phosphate 
B)  an RNA oligonucleotide with a 5'phosphate 
C)  a DNA oligonucleotide with a 3'phosphate 
D)  a DNA oligonucleotide with a 5'phosphate 
A)  an RNA oligonucleotide with a 3'phosphate 
B)  an RNA oligonucleotide with a 5'phosphate 
C)  a DNA oligonucleotide with a 3'phosphate 
D)  a DNA oligonucleotide with a 5'phosphate

Question 18

The Z-form of DNA

Accepted Answer

A)  does not exist in nature. 
B)  is right-handed. 
C)  tends to occur in purine-only sequences. 
D)  tends to occur in pyrimidine-only sequences. 
E)  tends to occur in alternating purine-pyrimidine sequences. 
A)  does not exist in nature. 
B)  is right-handed. 
C)  tends to occur in purine-only sequences. 
D)  tends to occur in pyrimidine-only sequences. 
E)  tends to occur in alternating purine-pyrimidine sequences.

Question 19

The nucleotide sequence of DNA is which level of structure?

Accepted Answer

A)  primary 
B)  secondary 
C)  tertiary 
D)  quaternary 
A)  primary 
B)  secondary 
C)  tertiary 
D)  quaternary

Question 20

The human genome has 3 × 109 base pairs (bp) of DNA If this were one continuous molecule and extended such that each nucleotide was separated from the adjacent nucleotide by 4 Å, as proposed in the Watson and Crick model, what would the end-to-end distance be?

Accepted Answer

A)  1 meter 
B)  1 centimeter 
C)  1000 centimeters 
D)  1014 Å 
A)  1 meter 
B)  1 centimeter 
C)  1000 centimeters 
D)  1014 Å

Exam 9: Nucleic Acids: How Structure Conveys Information

Which of the following statements concerning small nuclear RNA is true?

Calculate the length/diameter ratio for the extended E. coli DNA (4 Å between adjacent nucleotides). E. coli DNA has 2 × 106 bp.

Eukaryotic and prokaryotic ribosomes can be compared in all these ways, except:

In a melting profile for DNA, the absorbance at 260 nm increases as result of the disruption of the DNA structure. What is the fundamental physical basis for the absorbance increase?

Which of the following is the most common modification of nucleic acid bases?

Which of the following nucleobases is a purine?

The hydrogen bonding interactions in a Watson-Crick AT base-pair involve what units in the adenine base?

Supercoiling of DNA

Which of the following groups is not found in nucleosides?

In DNA structure, hydrophobic bonding via pi-clouds is referred to as

Which of the following can be an epigenetic change to chromatin?

The strands in the double helix

The double helix of DNA is which level of structure?

Which contains a phosphoanhydride bond?

Which of the following characteristics is associated with the B form of DNA?

The Tm for melting the double helix is:

The oligonucleotide AGGUCCAUUGAAp, is best described as

The Z-form of DNA

The nucleotide sequence of DNA is which level of structure?

The human genome has 3 × 109 base pairs (bp) of DNA If this were one continuous molecule and extended such that each nucleotide was separated from the adjacent nucleotide by 4 Å, as proposed in the Watson and Crick model, what would the end-to-end distance be?

Biochemistry and the Organization of Cells

Water: the Solvent for Biochemical Reactions

Amino Acids and Peptides

The Three-Dimensional Structure of Proteins

Protein Purification and Characterization Techniques

The Behavior of Proteins: Enzymes

The Behavior of Proteins: Enzymes, Mechanisms, and Control

Lipids and Proteins Are Associated in Biological Membranes

Biosynthesis of Nucleic Acids: Replication

Transcription of the Genetic Code: Biosynthesis of RNA

Protein Synthesis: Translation of the Genetic Message

Nucleic Acid Biotechnology Techniques

Viruses, Cancer, and Immunology

The Importance of Energy Changes and Electron Transfer in Metabolism

Carbohydrates

Glycolysis

Storage Mechanisms and Control in Carbohydrate Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Lipid Metabolism

Photosynthesis

The Metabolism of Nitrogen

Integration of Metabolism: Cellular Signaling

Filters

Calculate the length/diameter ratio for the extended E. coli DNA (4 Å between adjacent nucleotides). E. coli DNA has 2 × 10⁶ bp.

The T_m for melting the double helix is:

The human genome has 3 × 10⁹ base pairs (bp) of DNA If this were one continuous molecule and extended such that each nucleotide was separated from the adjacent nucleotide by 4 Å, as proposed in the Watson and Crick model, what would the end-to-end distance be?