Question 1

What is the approximate diameter of a DNA molecule?

Accepted Answer

A) A few picometers. 
B) A few Angstroms. 
C) A few nanometers. 
D) A few micrometers. 
A) A few picometers. 
B) A few Angstroms. 
C) A few nanometers. 
D) A few micrometers.

Question 2

In any species,the % (A +T)is equal to the % (G +C).

Accepted Answer

A) True 
 B)False

Question 3

The abbreviation dGp indicates

Accepted Answer

A) 5' deoxyguanylate. 
B) 3' deoxyguanylate. 
C) 3',5' deoxyguanylate. 
D) 5',3'deoxyguanylate. 
E) None of the above. 
A) 5' deoxyguanylate. 
B) 3' deoxyguanylate. 
C) 3',5' deoxyguanylate. 
D) 5',3'deoxyguanylate. 
E) None of the above.

Question 4

________ catalyze the hydrolysis of phosphodiester linkages to release nucleotide residues from only one end of a polynucleotide chain.

Accepted Answer

A) Topoisomerases 
B) Endonucleases 
C) Exonucleases 
D) Restriction enzymes 
A) Topoisomerases 
B) Endonucleases 
C) Exonucleases 
D) Restriction enzymes

Question 5

Cells fed 5-methyl uracil (radioactive in the methyl group)will form radioactive ________.

Accepted Answer

A) RNA 
B) DNA 
C) ribosomes 
D) tRNA 
E) A,C and D 
A) RNA 
B) DNA 
C) ribosomes 
D) tRNA 
E) A,C and D

Question 6

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

Accepted Answer

A) True 
 B)False

Question 7

Which of the following is mismatched?

Accepted Answer

A) Miescher - discovery of DNA. 
B) Avery - DNA is the genetic material. 
C) Watson - DNA structure. 
D) Hoppe-Seyler - DNA sequence. 
A) Miescher - discovery of DNA. 
B) Avery - DNA is the genetic material. 
C) Watson - DNA structure. 
D) Hoppe-Seyler - DNA sequence.

Question 8

Uracil is found in most RNA,while 5-methyluracil is found in most DNA.

Accepted Answer

A) True 
 B)False

Question 9

In proteins,amino acids are linked by peptide bonds;in polynucleotides,nucleotides are linked by

Accepted Answer

A) phosphoanhydride bonds. 
B) 3'-5'phosphodiester bonds. 
C) 5'-3'phosphodiester bonds. 
D) B and C. 
E) All of the above. 
A) phosphoanhydride bonds. 
B) 3'-5'phosphodiester bonds. 
C) 5'-3'phosphodiester bonds. 
D) B and C. 
E) All of the above.

Question 10

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 11

Alkaline hydrolysis with 0.1 M NaOH is an effective method of degrading RNA and DNA for determining the percent composition of each type of nucleotide monomer.

Accepted Answer

A) True 
 B)False

Question 12

The difference between dGMP and GMP is

Accepted Answer

A) the type of phosphodiester linkage. 
B) one hydroxyl group. 
C) syn versus anti conformation. 
D) the presence of DNA or RNA. 
A) the type of phosphodiester linkage. 
B) one hydroxyl group. 
C) syn versus anti conformation. 
D) the presence of DNA or RNA.

Question 13

The packaging of DNA in cells results in about a ________-fold reduction in length compared to the fully extended DNA (fully stretched out).

Accepted Answer

A) 10 
B) 700 
C) 8000 
D) 200,000 
A) 10 
B) 700 
C) 8000 
D) 200,000

Question 14

In any species,the ratio of the % (A +T)to the % (G +C)is constant.

Accepted Answer

A) True 
 B)False

Question 15

Which type of RNA carries activated amino acids to the ribosome for assembly into proteins?

Accepted Answer

A) rRNA. 
B) tRNA. 
C) mRNA. 
D) sRNA. 
A) rRNA. 
B) tRNA. 
C) mRNA. 
D) sRNA.

Question 16

Supercoiling of pure circular DNA is a result of ________.

Accepted Answer

A) underwinding or overwinding of the helix 
B) entanglements because of the long length of the strands 
C) the lack of associated histones 
D) the activity of exonucleases 
A) underwinding or overwinding of the helix 
B) entanglements because of the long length of the strands 
C) the lack of associated histones 
D) the activity of exonucleases

Question 17

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 18

According to Chargaff's observations of nucleotide composition of DNA samples

Accepted Answer

A) % of (G + 
C) + % of (A + T)= 100%. 
B) A = T. 
C) G = C. 
D) %A + %G + %C + %T = 100%. 
E) All of the above. 
A) % of (G + 
C) + % of (A + T)= 100%. 
B) A = T. 
C) G = C. 
D) %A + %G + %C + %T = 100%. 
E) All of the above.

Question 19

There are more acidic amino acid residues that basic amino acid residues in histone proteins to assist binding to the DNA backbone.

Accepted Answer

A) True 
 B)False

Question 20

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.

Exam 19: Nucleic Acids

What is the approximate diameter of a DNA molecule?

In any species,the % (A +T)is equal to the % (G +C).

The abbreviation dGp indicates

________ catalyze the hydrolysis of phosphodiester linkages to release nucleotide residues from only one end of a polynucleotide chain.

Cells fed 5-methyl uracil (radioactive in the methyl group)will form radioactive ________.

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

Which of the following is mismatched?

Uracil is found in most RNA,while 5-methyluracil is found in most DNA.

In proteins,amino acids are linked by peptide bonds;in polynucleotides,nucleotides are linked by

Restriction endonucleases recognize specific DNA sequences by ________.

Alkaline hydrolysis with 0.1 M NaOH is an effective method of degrading RNA and DNA for determining the percent composition of each type of nucleotide monomer.

The difference between dGMP and GMP is

The packaging of DNA in cells results in about a ________-fold reduction in length compared to the fully extended DNA (fully stretched out).

In any species,the ratio of the % (A +T)to the % (G +C)is constant.

Which type of RNA carries activated amino acids to the ribosome for assembly into proteins?

Supercoiling of pure circular DNA is a result of ________.

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

According to Chargaff's observations of nucleotide composition of DNA samples

There are more acidic amino acid residues that basic amino acid residues in histone proteins to assist binding to the DNA backbone.

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

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 Atp Synthesis

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

DNA Replication, repair, and Recombination

Transcription and RNA Processing

Protein Synthesis

Filters