Click here for more: Scholars nexus
BCH 3025 exam 2 Questions with Detailed
Verified Answers
The compound that consists of ribose linked by an N-glycosidic bond to N-9 of
adenine is:
A) a deoxyribonucleoside.
B) a purine nucleotide.
C) a pyrimidine nucleotide.
D) adenosine monophosphate.
E) adenosine.
Ans: E) adenosine
A major component of RNA but not of DNA is:
A) adenine.
B) cytosine.
C) guanine.
D) thymine.
E) uracil.
Ans: E) uracil.
The difference between a ribonucleotide and a deoxyribonucleotide is:
A) a deoxyribonucleotide has an —H instead of an —OH at C-2.
© Get it right 2025 Getaway - Stuvia US All rights reserved
,Click here for more: Scholars nexus
B) a deoxyribonucleotide has configuration; ribonucleotide has the configuration at C-
1.
C) a ribonucleotide has an extra —OH at C-4.
D) a ribonucleotide has more structural flexibility than deoxyribonucleotide.
E) a ribonucleotide is a pyranose, deoxyribonucleotide is a furanose.
Ans: A) a deoxyribonucleotide has an —H instead of an —OH at C-2.
Which one of the following is true of the pentoses found in nucleic acids?
A) C-5 and C-1 of the pentose are joined to phosphate groups.
B) C-5 of the pentose is joined to a nitrogenous base, and C-1 to a phosphate group.
C) The bond that joins nitrogenous bases to pentoses is an O-glycosidic bond.
D) The pentoses are always in the beta-furanose forms.
E) The straight-chain and ring forms undergo constant interconversion.
Ans: D) The pentoses are always in the beta-furanose forms
The phosphodiester bonds that link adjacent nucleotides in both RNA and DNA:
A) always link A with T and G with C.
B) are susceptible to alkaline hydrolysis.
C) are uncharged at neutral pH.
D) form between the planar rings of adjacent bases.
E) join the 3' hydroxyl of one nucleotide to the 5' hydroxyl of the next.
Ans: E) join the 3' hydroxyl of one nucleotide to the 5' hydroxyl of the next.
The phosphodiester bond that joins adjacent nucleotides in DNA:
© Get it right 2025 Getaway - Stuvia US All rights reserved
,Click here for more: Scholars nexus
A) associates ionically with metal ions, polyamines, and proteins.
B) is positively charged.
C) is susceptible to alkaline hydrolysis.
D) Links C-2 of one base to C-3 of the next.
E) links C-3 of deoxyribose to N-1 of thymine or cytosine.
Ans: A) associates ionically with metal ions, polyamines, and proteins.
The alkaline hydrolysis of RNA does not produce:
A) 2'- AMP.
B) 2',3'-cGMP.
C) 2'-CMP.
D) 3',5'-cAMP.
E) 3'-UMP.
Ans: D) 3',5'-cAMP
The DNA oligonucleotide abbreviated pATCGAC:
A) has 7 phosphate groups.
B) has a hydroxyl at its 3' end.
C) has a phosphate on its 3' end.
D) has an A at its 3' end.
E) violates Chargaff's rules.
Ans: B) has a hydroxyl at its 3' end
For the oligoribonucleotide pACGUAC:
© Get it right 2025 Getaway - Stuvia US All rights reserved
, Click here for more: Scholars nexus
A) the nucleotide at the 3' end has a phosphate at its 3' hydroxyl.
B) the nucleotide at the 3' end is a purine.
C) the nucleotide at the 5' end has a 5' hydroxyl.
D) the nucleotide at the 5' end has a phosphate on its 5' hydroxyl.
E) the nucleotide at the 5' end is a pyrimidine.
Ans: D) the nucleotide at the 5' end has a phosphate on its 5' hydroxyl.
The nucleic acid bases:
A) absorb ultraviolet light maximally at 280 nm.
B) are all about the same size.
C) are relatively hydrophilic.
D) are roughly planar.
E) can all stably base-pair with one another.
Ans: D) are roughly planar.
Which of the following statements concerning the tautomeric forms of bases such as
uracil is correct?
A) The all-lactim form contains a ketone group.
B) The lactam form contains an alcohol group.
C) The lactam form predominates at neutral pH.
D) They are geometric isomers.
E) They are stereoisomers.
Ans: C) The lactam form predominates at neutral pH.
In a double-stranded nucleic acid, cytosine typically base-pairs with:
© Get it right 2025 Getaway - Stuvia US All rights reserved
BCH 3025 exam 2 Questions with Detailed
Verified Answers
The compound that consists of ribose linked by an N-glycosidic bond to N-9 of
adenine is:
A) a deoxyribonucleoside.
B) a purine nucleotide.
C) a pyrimidine nucleotide.
D) adenosine monophosphate.
E) adenosine.
Ans: E) adenosine
A major component of RNA but not of DNA is:
A) adenine.
B) cytosine.
C) guanine.
D) thymine.
E) uracil.
Ans: E) uracil.
The difference between a ribonucleotide and a deoxyribonucleotide is:
A) a deoxyribonucleotide has an —H instead of an —OH at C-2.
© Get it right 2025 Getaway - Stuvia US All rights reserved
,Click here for more: Scholars nexus
B) a deoxyribonucleotide has configuration; ribonucleotide has the configuration at C-
1.
C) a ribonucleotide has an extra —OH at C-4.
D) a ribonucleotide has more structural flexibility than deoxyribonucleotide.
E) a ribonucleotide is a pyranose, deoxyribonucleotide is a furanose.
Ans: A) a deoxyribonucleotide has an —H instead of an —OH at C-2.
Which one of the following is true of the pentoses found in nucleic acids?
A) C-5 and C-1 of the pentose are joined to phosphate groups.
B) C-5 of the pentose is joined to a nitrogenous base, and C-1 to a phosphate group.
C) The bond that joins nitrogenous bases to pentoses is an O-glycosidic bond.
D) The pentoses are always in the beta-furanose forms.
E) The straight-chain and ring forms undergo constant interconversion.
Ans: D) The pentoses are always in the beta-furanose forms
The phosphodiester bonds that link adjacent nucleotides in both RNA and DNA:
A) always link A with T and G with C.
B) are susceptible to alkaline hydrolysis.
C) are uncharged at neutral pH.
D) form between the planar rings of adjacent bases.
E) join the 3' hydroxyl of one nucleotide to the 5' hydroxyl of the next.
Ans: E) join the 3' hydroxyl of one nucleotide to the 5' hydroxyl of the next.
The phosphodiester bond that joins adjacent nucleotides in DNA:
© Get it right 2025 Getaway - Stuvia US All rights reserved
,Click here for more: Scholars nexus
A) associates ionically with metal ions, polyamines, and proteins.
B) is positively charged.
C) is susceptible to alkaline hydrolysis.
D) Links C-2 of one base to C-3 of the next.
E) links C-3 of deoxyribose to N-1 of thymine or cytosine.
Ans: A) associates ionically with metal ions, polyamines, and proteins.
The alkaline hydrolysis of RNA does not produce:
A) 2'- AMP.
B) 2',3'-cGMP.
C) 2'-CMP.
D) 3',5'-cAMP.
E) 3'-UMP.
Ans: D) 3',5'-cAMP
The DNA oligonucleotide abbreviated pATCGAC:
A) has 7 phosphate groups.
B) has a hydroxyl at its 3' end.
C) has a phosphate on its 3' end.
D) has an A at its 3' end.
E) violates Chargaff's rules.
Ans: B) has a hydroxyl at its 3' end
For the oligoribonucleotide pACGUAC:
© Get it right 2025 Getaway - Stuvia US All rights reserved
, Click here for more: Scholars nexus
A) the nucleotide at the 3' end has a phosphate at its 3' hydroxyl.
B) the nucleotide at the 3' end is a purine.
C) the nucleotide at the 5' end has a 5' hydroxyl.
D) the nucleotide at the 5' end has a phosphate on its 5' hydroxyl.
E) the nucleotide at the 5' end is a pyrimidine.
Ans: D) the nucleotide at the 5' end has a phosphate on its 5' hydroxyl.
The nucleic acid bases:
A) absorb ultraviolet light maximally at 280 nm.
B) are all about the same size.
C) are relatively hydrophilic.
D) are roughly planar.
E) can all stably base-pair with one another.
Ans: D) are roughly planar.
Which of the following statements concerning the tautomeric forms of bases such as
uracil is correct?
A) The all-lactim form contains a ketone group.
B) The lactam form contains an alcohol group.
C) The lactam form predominates at neutral pH.
D) They are geometric isomers.
E) They are stereoisomers.
Ans: C) The lactam form predominates at neutral pH.
In a double-stranded nucleic acid, cytosine typically base-pairs with:
© Get it right 2025 Getaway - Stuvia US All rights reserved
