Question 1

The synthesis of proteins according to "the central dogma of molecular genetics" would require:

Accepted Answer

A) replication then translation. 
B) translation then replication. 
C) replication then transcription. 
D) transcription then translation. 
E) Any of these choices. 
A) replication then translation. 
B) translation then replication. 
C) replication then transcription. 
D) transcription then translation. 
E) Any of these choices.

Question 2

The automated synthesis of oligonucleotides

Accepted Answer

A) Uses dimethoxytrityl resin as solid phase. 
B) Is done in solution phase; the precipitated product is isolated by filtration. 
C) Is done in solid phase using an exchange resin and phosphoramidite monomers. 
D) Uses controlled pore glass as solid phase and phosphoramidite monomers. 
E) Is done in solution phase on a type of glass container that catalyzes the reaction. 
A) Uses dimethoxytrityl resin as solid phase. 
B) Is done in solution phase; the precipitated product is isolated by filtration. 
C) Is done in solid phase using an exchange resin and phosphoramidite monomers. 
D) Uses controlled pore glass as solid phase and phosphoramidite monomers. 
E) Is done in solution phase on a type of glass container that catalyzes the reaction.

Question 3

What is the secondary structure of DNA?

Accepted Answer

A) An alpha-helix 
B) A pleated sheet 
C) A flat sheet 
D) A double helix 
E) A random coil 
A) An alpha-helix 
B) A pleated sheet 
C) A flat sheet 
D) A double helix 
E) A random coil

Question 4

Which heterocyclic base found in RNA does not occur in DNA?

Accepted Answer

A) Guanine 
B) Thymine 
C) Cytosine 
D) Uracil 
E) Adenine 
A) Guanine 
B) Thymine 
C) Cytosine 
D) Uracil 
E) Adenine

Question 5

The molecular weight of tRNA is ___,compared with mRNA or rRNA; consequently,the solubility of tRNA is ___.

Accepted Answer

The answer of The molecular weight of tRNA is ___,compared...

Question 6

Which of the following statements about the polymerase chain reaction are true?

Accepted Answer

A) It generates a large number of copies of DNA. 
B) It polymerizes the short oligonucleotide strands formed during biosynthesis. 
C) It catalyzes the formation of mRNA. 
D) It needs a minuscule sample of DNA. 
E) Two of these choices. 
A) It generates a large number of copies of DNA. 
B) It polymerizes the short oligonucleotide strands formed during biosynthesis. 
C) It catalyzes the formation of mRNA. 
D) It needs a minuscule sample of DNA. 
E) Two of these choices.

Question 7

Supply the missing reagent(s)in the synthesis below.

Accepted Answer

A) PO43- and C6H5CH2OH 
B) PO43- and C6H5CH2Cl 
C)    
D) C6H5CH3 + POCl3 
E) C6H5CH2OH + H3PO4 
A) PO43- and C6H5CH2OH 
B) PO43- and C6H5CH2Cl 
C)    
D) C6H5CH3 + POCl3 
E) C6H5CH2OH + H3PO4

Question 8

Draw the structures corresponding to the following abbreviations: UMP and AMP.

Accepted Answer

The answer of Draw the structures corresponding to the following...

Question 9

What is a correct statement?

Accepted Answer

A) A gene contains a number of introns and exons. 
B) Introns are portions of the genes that are expressed. 
C) The exons are portions of the gene that are cut off during expression. 
D) Introns and exons can express independent from each other. 
E) Introns are spliced together after removal of exons. 
A) A gene contains a number of introns and exons. 
B) Introns are portions of the genes that are expressed. 
C) The exons are portions of the gene that are cut off during expression. 
D) Introns and exons can express independent from each other. 
E) Introns are spliced together after removal of exons.

Question 10

Which of the following is not a valid application of the PCR (polymerase chain reaction)?

Accepted Answer

A) Semen analysis in forensic investigations. 
B) Evolutionary biology. 
C) Detection of cytomegalovirus. 
D) Prenatal diagnosis of sickle cell anemia. 
E) All of these are valid applications of the PCR. 
A) Semen analysis in forensic investigations. 
B) Evolutionary biology. 
C) Detection of cytomegalovirus. 
D) Prenatal diagnosis of sickle cell anemia. 
E) All of these are valid applications of the PCR.

Question 11

Draw structures to represent the hydrogen bonding between adenine and thymine.

Accepted Answer

The answer of Draw structures to represent the hydrogen bonding...

Question 12

Consider the effect of nitrous acid on the adenine residue of a DNA strand.The product now resembles ___,and is likely to pair with ___,instead of with ___,leading to the possible mutations.

Accepted Answer

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

Question 13

Nitrous acid (HNO2)is a suspected mutagen because of its reaction with:

Accepted Answer

A) amine groups. 
B) ribose. 
C) phosphates. 
D) alcohols. 
E) ketones. 
A) amine groups. 
B) ribose. 
C) phosphates. 
D) alcohols. 
E) ketones.

Question 14

The primary structure of DNA is given by

Accepted Answer

A) The sequence of nucleosides in the DNA strand. 
B) The type of purine and pyrimidine bases along the DNA helix. 
C) The sequence of nucleotides in the DNA strand. 
D) The phosphate ester linkages in the DNA strand. 
E) The 3'-OH of the ribose in connection to the 5'-OH of the subsequent nucleotide. 
A) The sequence of nucleosides in the DNA strand. 
B) The type of purine and pyrimidine bases along the DNA helix. 
C) The sequence of nucleotides in the DNA strand. 
D) The phosphate ester linkages in the DNA strand. 
E) The 3'-OH of the ribose in connection to the 5'-OH of the subsequent nucleotide.

Question 15

A purine:

Accepted Answer

A) contains four nitrogens in the ring system. 
B) is bicyclic. 
C) can participate in hydrogen bonding. 
D) is a heterocyclic base. 
E) All of these choices. 
A) contains four nitrogens in the ring system. 
B) is bicyclic. 
C) can participate in hydrogen bonding. 
D) is a heterocyclic base. 
E) All of these choices.

Question 16

In a nucleotide unit,the components are sequentially linked:

Accepted Answer

A) monosaccharide-phosphate-heterocyclic base. 
B) amino acid-monosaccharide-phosphate. 
C) phosphate-monosaccharide-heterocyclic base. 
D) monosaccharide-amino acid-phosphate. 
E) heterocyclic base-phosphate-monosaccharide. 
A) monosaccharide-phosphate-heterocyclic base. 
B) amino acid-monosaccharide-phosphate. 
C) phosphate-monosaccharide-heterocyclic base. 
D) monosaccharide-amino acid-phosphate. 
E) heterocyclic base-phosphate-monosaccharide.

Question 17

Dimethoxytrityl is used as a protecting group on the 5'-OH of the carbohydrate in the synthesis of DNA.What is the species formed upon cleavage with acid? What factors contribute to its stability?

Accepted Answer

A) A dimethoxymethyl cation is formed.The cation is stabilized by hyperconjugation and by the donor effect of the OCH3 groups. 
B) A carbanion is formed and this is stabilized by resonance of the benzene rings and by the inductive effect of the OCH3 groups. 
C) A carbocation is formed and this stabilized by inductive effect of the OCH3 groups as well as by resonance of the negative charge on the benzene ring. 
D) A dimethoxytrityl cation is formed.The cation is stabilized by resonance of the benzene rings and by the donor effect of the OCH3 groups. 
E) A neutral dimethoxytrityl is formed.The lack of charge contributes to the easy of hydrolysis and the stability of the species released. 
A) A dimethoxymethyl cation is formed.The cation is stabilized by hyperconjugation and by the donor effect of the OCH3 groups. 
B) A carbanion is formed and this is stabilized by resonance of the benzene rings and by the inductive effect of the OCH3 groups. 
C) A carbocation is formed and this stabilized by inductive effect of the OCH3 groups as well as by resonance of the negative charge on the benzene ring. 
D) A dimethoxytrityl cation is formed.The cation is stabilized by resonance of the benzene rings and by the donor effect of the OCH3 groups. 
E) A neutral dimethoxytrityl is formed.The lack of charge contributes to the easy of hydrolysis and the stability of the species released.

Question 18

What product is likely to be formed from the reaction between an adenine residue on a nucleotide and nitrous acid? Explain the possible involvement of the product of this reaction in causing spontaneous mutation during replication.

Accepted Answer

The product resembles a guanine nucleoti

Question 19

The secondary structure of DNA was proposed by Watson and Crick to be a ___.

Accepted Answer

The answer of The secondary structure of DNA was proposed...

Question 20

The analytical data for DNA samples which led to generalizations such as (%G + %A) $\approx$ (%C + %T)came from the research of what individual?

Accepted Answer

A) James Watson 
B) Francis Crick 
C) Erwin Chargaff 
D) Arthur Kornberg 
E) Maurice Wilkins 
A) James Watson 
B) Francis Crick 
C) Erwin Chargaff 
D) Arthur Kornberg 
E) Maurice Wilkins

Exam 25: Nucleic Acids and Protein Synthesis

The synthesis of proteins according to "the central dogma of molecular genetics" would require:

The automated synthesis of oligonucleotides

What is the secondary structure of DNA?

Which heterocyclic base found in RNA does not occur in DNA?

The molecular weight of tRNA is ___,compared with mRNA or rRNA; consequently,the solubility of tRNA is ___.

Which of the following statements about the polymerase chain reaction are true?

Supply the missing reagent(s)in the synthesis below.

Draw the structures corresponding to the following abbreviations: UMP and AMP.

What is a correct statement?

Which of the following is not a valid application of the PCR (polymerase chain reaction)?

Draw structures to represent the hydrogen bonding between adenine and thymine.

Consider the effect of nitrous acid on the adenine residue of a DNA strand.The product now resembles ___,and is likely to pair with ___,instead of with ___,leading to the possible mutations.

Nitrous acid (HNO2)is a suspected mutagen because of its reaction with:

The primary structure of DNA is given by

A purine:

In a nucleotide unit,the components are sequentially linked:

Dimethoxytrityl is used as a protecting group on the 5'-OH of the carbohydrate in the synthesis of DNA.What is the species formed upon cleavage with acid? What factors contribute to its stability?

What product is likely to be formed from the reaction between an adenine residue on a nucleotide and nitrous acid? Explain the possible involvement of the product of this reaction in causing spontaneous mutation during replication.

The secondary structure of DNA was proposed by Watson and Crick to be a ___.

The analytical data for DNA samples which led to generalizations such as (%G + %A) ≈\approx≈ (%C + %T)came from the research of what individual?

The Basics

Families of Carbon

Acids and Bases

Nomenclature and Conformations of Alkanes and Cycloalkanes

Stereochemistry

Nucleophilic Reactions

Alkenes and Alkynes I

Alkenes and Alkynes II

Nuclear Magnetic Resonance and Mass Spectrometry

Radical Reactions

Alcohols and Ethers

Alcohols From Carbonyl Compounds

Conjugated Unsaturated Systems

Aromatic Compounds

Reactions of Aromatic Compounds

Aldehydes and Ketones

Carboxylic Acids and Their Derivatives

Reactions at the Α Carbon of Carbonyl Compounds

Condensation and Conjugate Addition Reactions of Carbonyl Compounds

Amines

Transition Metal Complexes

Carbohydrates

Lipids

Amino Acids and Proteins

Filters

The molecular weight of tRNA is _,compared with mRNA or rRNA; consequently,the solubility of tRNA is _.

Consider the effect of nitrous acid on the adenine residue of a DNA strand.The product now resembles _,and is likely to pair with _,instead of with ___,leading to the possible mutations.

Nitrous acid (HNO₂)is a suspected mutagen because of its reaction with:

The analytical data for DNA samples which led to generalizations such as (%G + %A) $\approx$ (%C + %T)came from the research of what individual?