Question 1

Alkaline hydrolysis of RNA produces a mixture of 2ʹ and 3ʹ - nucleotides. Hydrolysis by RNase A produces on the 3ʹ-nucleotides.

Accepted Answer

A) True 
 B)False

Question 2

Bacteria produce many restriction endonucleases. What prevents these enzymes from degrading the host DNA?

Accepted Answer

A)  A bacterium will produce endonucleases that recognize sequences that are not present in its own DNA. 
B)  The strong association between the histones and bacterial DNA prevent the endonucleases from acting on them. 
C)  The endonucleases are transported out of the cell so quickly they cannot significantly affect the host DNA. 
D)  The host DNA is specifically methylated and is therefore protected from cleavage. 
A)  A bacterium will produce endonucleases that recognize sequences that are not present in its own DNA. 
B)  The strong association between the histones and bacterial DNA prevent the endonucleases from acting on them. 
C)  The endonucleases are transported out of the cell so quickly they cannot significantly affect the host DNA. 
D)  The host DNA is specifically methylated and is therefore protected from cleavage.

Question 3

Stem-loop is a type of secondary structure not usually found in

Accepted Answer

A)  rRNA. 
B)  tRNA. 
C)  mRNA. 
D)  small RNA. 
A)  rRNA. 
B)  tRNA. 
C)  mRNA. 
D)  small RNA.

Question 4

ʺFive prime to three primeʺ description of a DNA strand refers to

Accepted Answer

A)  the phosphorylated 5ʹ carbon at one end, the 3ʹ at the other end. 
B)  the location of the hydroxyl groups. 
C)  the phosphodiester backbone of DNA. 
D)  the phosphorylated 5ʹ carbon on one sugar and the 3ʹ carbon on the next sugar. 
A)  the phosphorylated 5ʹ carbon at one end, the 3ʹ at the other end. 
B)  the location of the hydroxyl groups. 
C)  the phosphodiester backbone of DNA. 
D)  the phosphorylated 5ʹ carbon on one sugar and the 3ʹ carbon on the next sugar.

Question 5

It is not possible for linear DNA to be supercoiled. Only circular DNA, which has no ends, can have regions of supercoiling.

Accepted Answer

A) True 
 B)False

Question 6

Restriction endonucleases recognize specific DNA sequences by .

Accepted Answer

A)  contacting base pairs in the major groove 
B)  inserting amino acid side chains between the base pairs and interrupting the stacking interactions 
C)  hydrogen bonding with base pairs in the minor groove 
D)  detecting base pair-depended variations in the sugar-phosphate backbone 
A)  contacting base pairs in the major groove 
B)  inserting amino acid side chains between the base pairs and interrupting the stacking interactions 
C)  hydrogen bonding with base pairs in the minor groove 
D)  detecting base pair-depended variations in the sugar-phosphate backbone

Question 7

plays an important role in storing the energy needed for the unwinding of DNA during replication, recombination, repair and transcription.

Accepted Answer

A)  A high percent of G:C base pairs 
B)  The charge on basic side chains of histone proteins 
C)  Negative supercoiling 
D)  Overwinding of the helix 
A)  A high percent of G:C base pairs 
B)  The charge on basic side chains of histone proteins 
C)  Negative supercoiling 
D)  Overwinding of the helix

Question 8

Which does not apply to most bacterial DNA?

Accepted Answer

A)  circular 
B)  relaxed 
C)  not packed into nucleosomes 
D)  supercoiled 
A)  circular 
B)  relaxed 
C)  not packed into nucleosomes 
D)  supercoiled

Question 9

Deoxyribonucleosides and ribonucleotides contain two hydroxyl groups that can be phosphorylated.

Accepted Answer

A) True 
 B)False

Question 10

The rise and pitch of B-DNA are 0.33 nm and 3.40 nm, respectively. About how many helical turns are there in a fragment 1 mm in length?

Accepted Answer

A)  3030 
B)  294 
C)  330 
D)  0.0034 
E)  Cannot calculate from the information given. 
A)  3030 
B)  294 
C)  330 
D)  0.0034 
E)  Cannot calculate from the information given.

Question 11

What is the effect of incubating a mixture of RNA and DNA with 0.1 M NaOH?

Accepted Answer

A)  RNA is hydrolyzed to nucleoside monophosphates. 
B)  DNA is hydrolyzed to nucleoside monophosphates. 
C)  Both RNA and DNA are hydrolyzed to nucleoside monophosphates. 
D)  No effect. RNA and DNA are resistant to base hydrolysis. 
A)  RNA is hydrolyzed to nucleoside monophosphates. 
B)  DNA is hydrolyzed to nucleoside monophosphates. 
C)  Both RNA and DNA are hydrolyzed to nucleoside monophosphates. 
D)  No effect. RNA and DNA are resistant to base hydrolysis.

Question 12

The tetranucleotide AGTC in DNA) has a free hydroxyl group on

Accepted Answer

A)  A. 
B)  A, G, T, and C. 
C)  C. 
D)  G, T, and C. 
A)  A. 
B)  A, G, T, and C. 
C)  C. 
D)  G, T, and C.

Question 13

Messenger RNA is the least stable type of cellular ribonucleic acid.

Accepted Answer

A) True 
 B)False

Question 14

Purines which are found mainly in both deoxyribonucleotides and ribonucleotides are

Accepted Answer

A)  thymine and cytosine. 
B)  thymine, cytosine and uracil. 
C)  adenine and thymine. 
D)  guanine and cytosine. 
E)  adenine and guanine. 
A)  thymine and cytosine. 
B)  thymine, cytosine and uracil. 
C)  adenine and thymine. 
D)  guanine and cytosine. 
E)  adenine and guanine.

Question 15

It is possible to synthesize DNA containing specific polynucleotide bases today.

Accepted Answer

A) True 
 B)False

Question 16

Which is not a difference between B-DNA and A-DNA?

Accepted Answer

A)  A-DNA forms under more dehydrating conditions than B-DNA. 
B)  For polynucleotide strands containing the same number of nucleotides, the A-DNA strand will be shorter from end-to-end than the corresponding B-DNA. 
C)  Both are helical, but B-DNA is right-handed and A-DNA is left-handed. 
D)  The planes of the nitrogenous bases are not perpendicular to the helix axis in A-DNA. 
A)  A-DNA forms under more dehydrating conditions than B-DNA. 
B)  For polynucleotide strands containing the same number of nucleotides, the A-DNA strand will be shorter from end-to-end than the corresponding B-DNA. 
C)  Both are helical, but B-DNA is right-handed and A-DNA is left-handed. 
D)  The planes of the nitrogenous bases are not perpendicular to the helix axis in A-DNA.

Question 17

The abbreviation pdAp indicates

Accepted Answer

A)  5ʹ, 3ʹ deoxyadenylate. 
B)  3ʹ, 5ʹ deoxyadenylate. 
C)  5ʹ deoxyadenylate. 
D)  3ʹ deoxyadenylate. 
E)  None of the above 
A)  5ʹ, 3ʹ deoxyadenylate. 
B)  3ʹ, 5ʹ deoxyadenylate. 
C)  5ʹ deoxyadenylate. 
D)  3ʹ deoxyadenylate. 
E)  None of the above

Question 18

RNA does not have a double strand form.

Accepted Answer

A) True 
 B)False

Question 19

There are many viruses whose entire genome is Z-DNA.

Accepted Answer

A) True 
 B)False

Question 20

The recognition site of some restriction enzymes are shown. Which will produce sticky ends?

Accepted Answer

A)  EcoRI G↓AATTC 
B)  SmaI CCC↓GGG 
C)  XhoI C↓TCGAG 
D)  both EcoRI and XhoI 
E)  All the enzymes shown will leave sticky ends. 
A)  EcoRI G↓AATTC 
B)  SmaI CCC↓GGG 
C)  XhoI C↓TCGAG 
D)  both EcoRI and XhoI 
E)  All the enzymes shown will leave sticky ends.

Exam 19: Nucleic Acids

Alkaline hydrolysis of RNA produces a mixture of 2ʹ and 3ʹ - nucleotides. Hydrolysis by RNase A produces on the 3ʹ-nucleotides.

Bacteria produce many restriction endonucleases. What prevents these enzymes from degrading the host DNA?

Stem-loop is a type of secondary structure not usually found in

ʺFive prime to three primeʺ description of a DNA strand refers to

It is not possible for linear DNA to be supercoiled. Only circular DNA, which has no ends, can have regions of supercoiling.

Restriction endonucleases recognize specific DNA sequences by .

plays an important role in storing the energy needed for the unwinding of DNA during replication, recombination, repair and transcription.

Which does not apply to most bacterial DNA?

Deoxyribonucleosides and ribonucleotides contain two hydroxyl groups that can be phosphorylated.

The rise and pitch of B-DNA are 0.33 nm and 3.40 nm, respectively. About how many helical turns are there in a fragment 1 mm in length?

What is the effect of incubating a mixture of RNA and DNA with 0.1 M NaOH?

The tetranucleotide AGTC in DNA) has a free hydroxyl group on

Messenger RNA is the least stable type of cellular ribonucleic acid.

Purines which are found mainly in both deoxyribonucleotides and ribonucleotides are

It is possible to synthesize DNA containing specific polynucleotide bases today.

Which is not a difference between B-DNA and A-DNA?

The abbreviation pdAp indicates

RNA does not have a double strand form.

There are many viruses whose entire genome is Z-DNA.

The recognition site of some restriction enzymes are shown. Which will produce sticky ends?

Introduction to Biochemistry

Water

Amino Acids and the Primary Structures of Proteins

Proteins: Three-Dimensional Structure and Function

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Lipids and Membranes

Introduction to Metabolism

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Dna Replication, Repair, and Recombination

Transcription and Rna Processing

Protein Synthesis

Recombinant Dna Technology

Filters