Deck 10: Nucleotides and Nucleic Acids

Question 1

Which is a six-membered heterocyclic aromatic ring?

A) pyrimidine
B) purine
C) anose
D) sugar portion of DNA
E) ribonucleotide

Answer 1

A

Question 2

All are characteristics of pyrimidines EXCEPT:

A) six-membered ring.
B) heterocyclic.
C) conjugated.
D) fused five membered rings.
E) two nitrogens separated by a carbonyl.

Answer 2

D

Question 3

The net charge on nucleotide monophosphates is:

A) +1
B) 0
C) −1
D) −2
E) −3

Answer 3

D

Question 4

All of the following are important characteristics of DNA EXCEPT:

A) a 1:1 ratio between pyrimidine residues and purine residues.
B) adenine base pairs with uracil.
C) hydrogen bonding between base pairs.
D) information contained in the sequence of one strand conserved in the sequence of other strand.
E) information is accessed through transcription of the information into RNA.

Question 5

____ is the most oxidized state for a purine derivative and is ____ found in nucleic acids.

A) Guanine; always
B) Adenine; always
C) Hypoxanthine; never
D) Xanthine; always
E) Uric acid; never

Question 6

Nucleotide triphosphates and nucleotide diphosphates often form stable complexes with:

A) Na⁺
B) Fe⁺³
C) K⁺
D) Mg⁺²
E) None of the above.

Question 7

What is the nucleotide sequence of the DNA strand that is complementary to 5'-ATCGCAACTGTCACTA-3'?

A) 5'-TAGCGTTGACAGTGAT-3'
B) 5'-UAGUGACAGUUGCGAU-3'
C) 5'-TAGCGTTGACAGTGAT-3'
D) 5'-TAGTGACAGTTGCGAT-3'
E) 5'-ATCACTGTCAACGCTA-3'

Question 8

Nucleosides are relatively stable to ____ hydrolysis, and pyrimidine nucleotides are stable to ____ hydrolysis, but purine nucleotides are unstable to ____ hydrolysis.

A) base; acid; acid
B) base; base; acid
C) acid; base; base
D) acid; acid; base
E) none are true

Question 9

Nucleotides have a nitrogenous base linked to a sugar by a:

A) α-anhydride bond.
B) β-ester bond.
C) α-N-amide bond.
D) β-N-acetal (glycosidic) bond.
E) α-N-hemiacetal bond.

Question 10

Which molecule contains an phosphoanhydride bond?

A) DNA
B) AMP
C) UDP
D) RNA
E) cAMP

Question 11

In phosphoryl group transfer reactions, the ____ of the nucleotide serves as an information symbol, channeling the nucleotide to appropriate metabolic activities.

A) sugar
B) diphosphate anhydride
C) sugar-phosphate ester
D) base
E) none are true

Question 12

Which of the following properties describe both purines and pyrimidines?

A) they are aromatic
B) they are composed of 6-membered rings
C) they exhibit strong absorption of UV light
D) they always contain a carbonyl group
E) both A and C are correct

Question 13

Which of the following statements regarding the structure of DNA is correct?

A) the two strands are parallel.
B) the two strands are held together by intrachain hydrogen bonds.
C) the two strands have complementary base pairing.
D) the hydrogen bonding that holds the helix together is always between two purines or between two pyrimidines.
E) the ratio of adenine to guanine is the same in all organisms.

Question 14

cAMP and cGMP are ____ with phosphate esterified as a cyclic ____ and are important as ____ of cellular metabolism.

A) nucleotides; phosphodiesters; inhibitors
B) nucleotides; phosphomonoesters, regulators
C) nucleotides; phosphodiesters, regulators
D) nucleosides; phosphomonoesters, stimulators
E) all of the above

Question 15

Complete hydrolysis of nucleic acids liberates all of the following EXCEPT:

A) 2-deoxyribose from DNA.
B) nitrogenous bases.
C) amino acids.
D) phosphoric acid.
E) ribose from RNA.

Question 16

All of the following are examples of nucleotide functions EXCEPT:

A) CTP in phospholipid synthesis.
B) UTP in complex carbohydrate synthesis.
C) ATP in energy for the cell.
D) GTP in protein synthesis.
E) TTP in phosphoryl group transfers.

Question 17

The convention in all notations of nucleic acid structure is to read the polynucleotide chain from the ____ of the polymer to the ____.

A) poly U head; poly A tail
B) 3'-end; 5'-tail
C) 5'-end; 3'-end
D) poly-p head; 5'-end
E) none are true

Question 18

In a sample of double-stranded DNA containing 32% cytosine, the percentage of adenine would be:

A) 32%
B) 68%
C) 18%
D) 0%
E) insufficient information to answer question

Question 19

In a double-stranded nucleic acid, guanine typically base-pairs with:

A) adenosine.
B) uracil.
C) inosine.
D) thymine.
E) cytosine.

Question 20

All are important functional groups participating in H-bond formation EXCEPT:

A) amino group of the cytosine, adenine, and guanine.
B) the ring nitrogens at position 3 of pyrimidines and 1 of purines.
C) the electronegative oxygen atoms.
D) the electron density in the double bonds of the bases.
E) the carbonyl group at position 4 of uracil and thymine, position 2 of cytosine, and position 6 of guanine.

Question 21

Prokaryotic chromosomes are typically ____, while eukaryotic chromosomes are ____

A) circular; linear and richly protein-associated
B) circular and richly protein-associated; linear
C) linear and richly protein-associated; circular
D) linear; circular and richly protein-associated
E) none are true.

Question 22

All are necessary for restriction endonuclease mapping of DNA molecules EXCEPT:

A) Determining the 5'- and/or 3'-ends of the molecule.
B) Electrophoresis of fragments.
C) Hydrolysis with two or more endonucleases.
D) Knowing where each endonuclease hydrolyzes.
E) All are true.

Question 23

Describe the types of restriction endonucleases.​

Question 24

____ are important in the processing of eukaryotic gene transcripts into mature messenger RNAs for export from the nucleus into cytoplasm.

A) snRNAs as snRNPs
B) tRNAs
C) rRNAs
D) siRNAs
E) stRNAs

Question 25

____ are attached to hnRNAs and mRNAs after transcription has been completed and is essential for efficient translation and stability of the mRNAs.

A) exons
B) entrons
C) poly(A) tails
D) poly(U) tails
E) All are true

Question 26

If a restriction site of 6 bases starts with 5'-TGG, what are the last three bases in the sequence?

A) 5'-ACC-3'
B) 5'-GGT-3'
C) 5'-CCA-3'
D) 5'-TGG-3'
E) none of the above

Question 27

Discuss nucleosides.​

Question 28

In eukaryotic cells, a class of ____- and ____-rich proteins called ____ interact ionically with the anionic phosphate groups in the DNA backbone to form ____.

A) lysine; leucine; prions; ribosomes
B) arginine; lysine; histones; nucleosomes
C) arginine; alanine; histones; nucleosomes
D) arginine; lysine; prions; ribosomes
E) none are true.

Question 29

Eukaryotic mRNAs are synthesized in the nucleus, are called ____, and contain noncoding regions called ____ because they intervene between coding regions called ____.

A) poly A RNAs; noncodons; codons
B) poly A RNAs; intervening sequences; codons
C) heterogeneous nuclear RNAs; intervening sequences (introns); codons
D) heterogeneous nuclear RNAs; intervening sequences (introns); exons
E) none of the above.

Question 30

In eukaryotic cells, DNA is found principally in the nucleus, but it also occurs in ____ and in ____.

A) ribosomes; mitochondria
B) mitochondria; chloroplasts
C) chloroplasts; peroxisomes
D) peroxisomes; vacuoles
E) vacuoles; mitochondria

Question 31

RNA is ____ stable to alkaline hydrolysis than DNA because RNA's vicinal ____ group makes the 3'-phosphodiester bond susceptible to ____ cleavage.

A) less; 3'-OH; nucleophilic
B) less; 2'-OH; nucleophilic
C) more; 2'-OH; electrophilic
D) more; 2'-OH; nucleophilic
E) more; 3'-OH; electrophilic

Question 32

All are true for enzymes that cleave nucleic acids EXCEPT:

A) They are of the lyase class of enzymes.
B) They are called nucleases.
C) They belong to the sub-class of phosphodiesterases.
D) They are found in all cells for "house keeping", and secreted by the pancreas for digestion.
E) They are found in fungi and snake venoms

Question 33

Inosine, one of the common alternative bases found in RNA, is shown below. How would inosine form hydrogen bonds in a double helical section of RNA?

A) 1 H-bond donor group, 0 H-bond acceptor groups
B) 0 H-bond donor groups, 1 H-bond acceptor group
C) 1 H-bond donor group, 1 H-bond acceptor group
D) 2 H-bond donor groups, 1 H-bond acceptor group
E) 1 H-bond donor group, 2 H-bond acceptor groups

Question 34

Discuss the types and functions of RNA.​

Question 35

Which of the following statements correctly identifies a type II restriction endonuclease?

A) They work on both DNA and RNA.
B) They recognize a palindromic sequence and cut just before the palindromic sequence.
C) The result of this endonuclease is blunt ends.
D) They degrade DNA by subsequently removing bases from each end.
E) They cut DNA only at sites in specific nucleotide sequences with a two-fold axis of symmetry.

Question 36

Explain the packaging of DNA in eukaryotic cells.​

Question 37

Discuss gene silencing brought about by small interfering RNAs (siRNAs).​

Question 38

30S rRNA is a designation of the ____ of the RNA molecule.

A) number of sugars
B) sedimentation coefficient
C) splicing coefficient
D) sequence repeats
E) splicing number

Question 39

Which of the following restriction sites would provide staggered 3'ends? The restriction site in each sequence is shown with an arrow.

A) 5'-T↓TCGAA-3'
B) 5'-GTT↓AAC-3'
C) 5'-CCC↓GGG-3'
D) 5'-CTGCA↓G-3'
E) none of the above