Biochemistry 3 (tests)
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- 1.The component (s) of DNA which is responsible for the absorbanc band at 250-270 nm is
- A.
Bases, pentoses, and phosphates all contribute
- B.
Only bases
- C.
Only bases and pentoses
- D.
Only pentoses and phosphates
- 2.To what target sequence on DNA is the oligonucleotide pAATTCCGG complementary? (sequence are written as 5'-3')
- A.
TTAAGGCC
- B.
CCGGAATT
- C.
UUAAGGCC
- D.
CCGGAAUU
- 3.In eukaryotic cells, the only RNA molecule which has a poly (A) tail attached to the 3' end is
- A.
MRNA
- B.
TRNA
- C.
SS RNA
- D.
All rRNA's
- 4.The RNA molecules which are involved in processing the hnRNA are
- A.
MRNA
- B.
TRNA
- C.
RRNA
- D.
SnRNA
- 5.Partial digestion of the oligonucleotide d-AGTACAA by pancreatic phosphodiesterase (a "b" cutter) would result in which set of products?
- A.
AGP, pAC, pAA
- B.
AGPp, AC, pAA
- C.
AGp, TAp, CAA
- D.
AG, TAp, pCCA
- 6.Which of the following is not a characteristic for DNA synthesis?
- A.
DNA polymerase adds nucleotides in a 5' --> 3' direction
- B.
A primer strand of DNA must contain a free 3'-OH end
- C.
The primer strand of DNA determines which nucleotides are added next
- D.
The correct complementary hydrogen bonding between base pairs is the primary check on the fidelity of the newly synthesized DNA
- 7.A DNA is found to exhibit a melting temperature of 75 degrees Celsius in 0.1M NaCl. Under what experimental conditions would the Tm be increased? (pg 372)
- A.
Decreasing the concentration of DNA
- B.
Increasing the concentration of NaCl in the solution
- C.
Adding 1% urea (an organic denaturant)
- D.
All of the above
- 8.Which of the following characteristics is associated with the B form of DNA?
- A.
The sugars are located in the interior of the double helix
- B.
B
- 9.A feature which is distinctive to Z-DNA is
- A.
A left-handed helix
- B.
it has 12 bases per turn
- C.
It is found in vivox
- D.
All of the above
- 10.
- A.
500
- B.
50
- C.
450
- D.
350
- 11.The linking number of a highly supercoiled plasmid can be readily changed without producing a relaxed DNA by
- A.
Changing the temperature
- B.
Increasing salt concentration
- C.
The action of topoisomerase
- D.
The action of a nuclease such as pancreatic DNAse
- 12.Under which of the following conditions does the melting temperature for the denaturation of duplex DNA decrease?
- A.
Higher salt concentration in the buffer
- B.
Higher GC content in the DNA
- C.
PH higher than 10 in the buffer
- D.
Longer DNA fragments
- 13.
- A.
ATGCATGCATGCATGC / TACGTACGTACGTACG
- B.
AAAAAAAAACCCCCCCCC / TTTTTTTTTGGGGGGGGC
- C.
ATATATATGCGCGCGCGC / TATATATACGCGCGCGCG
- D.
CATTAAGCAGTGCTTAAGA / GAATTCGTCACGAATTCT
- 14.Which of the following statements is incorrect when dsDNA is denatured? (pg 371-2)
- A.
The absorbance at 260 decreases about 40%
- B.
The hgiher the G+C content, the higher the melting temperature
- C.
The transition from dsDNA to ssDNA is highly cooperative
- D.
The fraction of DNA that is single stranded is 0.5 at its Tm
- 15.
- A.
It serves as the start point for the new DNA strand
- B.
It serves as a guide in determining the next nucleotide to be added by the polymerase
- C.
It increases the processivity of the DNA polymerase
- D.
It is essential for the 3-5' exonuclease activity
- 16.In the repair of DNA, the E.coli DNA polymerase invovled performs which function in addition to its polymerase activity?
- A.
It recognizes the abnormality in the duplex DNA structure.
- B.
It nicks the DNA to provide a 3'-OH
- C.
It removes the damaged section of DNA with its 5'-3' exonuclease activity
- D.
It ligates the DNA after the repair synthesis
- 17.
- A.
It insures the fidelity of the newly synthesized DNA strand
- B.
The DNA polymerases require a preexisting strand with a nucleotide having a 3'-OH.
- C.
The DNA polymerases require a preexisting strand with a nucleotide having a 5'-OH.
- D.
All of the above are correct
- 18.The Klenow fragment of E. coli DNA polymerase I can be used to add nucleotides to a DNA with staggered ends if the ends...
- A.
Are recessed with 5'-phosphates
- B.
Are recessed with 3'-OHs
- C.
Are extended with 5'-phosphates
- D.
Are extended with 3'-OHs
- 19.Which E. coli DNA polymerase is responsible for the repair of DNA?
- A.
DNA polymerase I
- B.
Klenow fragment
- C.
DNA polymerase II
- D.
DNA polymerase III
- 20.The Klenow fragment from E.coli DNA polymerase contains all of the following except (pg 993)
- A.
DNA polymerase activity
- B.
5'-3' exonuclease activity
- C.
The large fragment from the C-terminal end of the polymerase
- D.
3'-5' exonuclease activity
- 21.E. coli replication on the lagging strand (pg 1002)
- A.
Is primarily carried out by DNA polymerase I
- B.
Is synthesized continuously
- C.
This DNA strand is synthesized in a 3'-5' direction of synthesis
- D.
Is initially synthesized as Okazaki fragments
- 22.Which one of the following characteristics ls not associated with E.coli primase?
- A.
It syntheslzes the RNA primer in DNA repllcation.
- B.
It is a specific RNA polymerase
- C.
It is essential for DNA replication
- D.
It is also a gyrase
- 23.The polymerase which plays a similar role as that of Prokaryotic Pol III in eukaryotic replication is (pg 1006)
- A.
DNA polymerase alpha
- B.
DNA polymerase alpha
- C.
DNA polymerase delta
- D.
DNA polymerase alpha
- 24.Which is not a property of E.coli DNA polymerase III?
- A.
It is responsible for incorporating most of the nucleotides in the lagging strand
- B.
It synthesizes most of the leading strand prior to aiding in the synthesis of the lagging strand
- C.
It contains a 3' to 5' exonuclease activity
- D.
It synthesizes the leading strand and the lagging strand at the same time
- 25.Which of the following enzymes possesses a 5' to 3' exonuclease activity?
- A.
Primase
- B.
DNA polymerase I
- C.
DNA polymerase III
- D.
DNA gyrase
- 26.Which statement is INCORRECT about E. coli DNA polymerase I? (pg 991)
- A.
The cell contains more molecules of DNA pol I than DNA pol III
- B.
DNA pol I is a single polypeptide with three domains
- C.
DNA pol I is involved in the repair of UV damaged DNA
- D.
DNA pol I has a larger turnover number than DNA pol III
- 27.Which statement is INCORRECT about E. coli DNA ligase?
- A.
It functions int he replication but not in the repair of DNA
- B.
It forms a "DNA-AMP" covalent complex during the reaction it catalyzes
- C.
It can seal nicks in the dsDNA as long as the adjacent nucleotides surrounding the nick contain a free 3' hydroxyl and a 5' phosphate
- D.
It catalyzes the formation of a phosphoester bond in dsDNA
- 28.Which E. coli enzyme has the greatest frequency of incorporating the incorrect nucleotide into its nucleic acid polymer?
- A.
RNA polymerase
- B.
DNA polymerase I
- C.
DNA polymerase III
- D.
Klenow fragment from DNA polymerase I
- 29.Which one of the following DNA sequences is palindromic?
- A.
GCGCGCGCGCGC / CGCGCGCGCGCG
- B.
GGGGGGGGCGA / CCCCCCCCGCC
- C.
ATGCATGC / TACGTACG
- D.
GGCCGGCCGG / CCGGCCGGCC
- 30.The synthesis of the DNA strand is thermodynamically driven by
- A.
The dNTP hydrolysis to produce the incorporated NMP and the PPi
- B.
The nature of the strong connecting bonds formed int he linked nucleotides
- C.
The dNTP hydrolysis and the subsequent hydrolysis of PPi by pyrophosphatase
- D.
The inherent stability of the synthesized DNA polynucleotide
- 31.The promoter site is
- A.
The start base for transcription in DNA
- B.
The binding site in DNA for regulatory proteins which stimulate or further promote the level of transcription
- C.
The site on DNA at which RNA polymerase binds to initiate transcription
- D.
The general region of DNA downstream from the start site.
- 32.Which of the following factors or subunits is contained within the core RNA polymerase in prokaryotic organisms? (pg 1016)
- A.
Alpha, beta, and beta'
- B.
Alpha, beta, beta', and gamma holoenzyme
- C.
TFIID, SP1 and enhancer protein
- D.
TF IIIA, TFIIIB, and TFIIIC
- 33.The subunit in E. coli RNA polymerase which is required fro recognition of the promoter sequence is
- A.
Alpha
- B.
Beta
- C.
Beta prime
- D.
Gamma
- 34.RNA polymerase II (pg 102)
- A.
Is located int he nucleolus and transcribes the major ribosomal RNA genes
- B.
Is located in the nucleoplasm (general nucleus) and transcribes protein-encoding genes
- C.
Transcribes the 5S RNA genes
- D.
Transcribes RNAs associated with mRNA processing (SNRP's)
- 35.The lac operon includes (pg 1031)
- A.
The structural genes for lacZ, lacY, and lacA
- B.
The three structural genes listed in (a) and the operator and promoter sequences for these genes
- C.
All elements listed in (b) and the lacI gene
- D.
All elements in (c) and the promoter for lacI
- 36.Which statemnt is INCORRECT aobut enhancer sequences in eukaryotes (pg 1015)
- A.
They can occur within a gene
- B.
They can occur either 3' or 5' to the gene
- C.
They can be in either orientation
- D.
They can be placed at different distances from the gene without changing their influence
- 37.Which statement is INCORRECT about eh synthesis of RNA by RNA polymerase in E. coli?
- A.
A
- B.
B
- 38.Prokaryotic genes have conserved DNA sequences centered around -10 and -35 before the initiation point of transcription. THese regions contain a binding site for:
- A.
The rho protein
- B.
DNA polymerase
- C.
Ribosomes
- D.
RNA polymerase holoenzyme
- 39.A strain of E. coli produces the same high level of beta-galactosidase regardless of the concentration of lactose in the medium. This strain most liekly contains a deletion mutation in the gene (Note: you may assume that the deletion mutation causes loss of normal function) (pg 10)
- A.
Lac 1
- B.
Lac 2
- C.
Gene coding for the gamma-subunit of RNA polymerase
- D.
Gene encoding the catabolite activator protein
- 40.Which statement is CORRECT about RNA polymerase in E. coli?
- A.
It transcribes the DNA sense strand
- B.
It transcribes the DNA antisense strand
- C.
It transcribes only protein genes
- D.
It translates DNA into protein
- 41.Which statement is INCORRECT about a typical E. coli promoter? (pg 1019)
- A.
It consists of approximately 60 bp of dsDNA
- B.
It is recognized and bound by the gamma-subunit of RNA polymerase holoenzyme
- C.
The base sequences centered at -10 of various promoters are not identical but almost always differ by two or fewer bases from the consensus sequence
- D.
It contains a "GC rich" consensus seuqence centered at =10 called the Pribnow box
- 42.The reason why DNA does not contain uracyl is because
- A.
Uracyl forms unstable hydrogen bonds
- B.
Cytosine spontaneously becomes uracyl
- C.
Thymine can do the same function as uracyl
- D.
Uracyl can only from glycosidic bonds with ribose
- 43.In the Sanger's DNA sequencing method of the following oligonucleotide, what will be the sequence read form the gel? AATCGATTCGGGCTATA. The primer is 4 nucleotides long. (pg 359)
- A.
AATCGATTCGGGCTATA
- B.
TTAGCTAAGCCCGATAT
- C.
The primer strand plus TTAGCTAAGCCCG
- D.
TTAGCTAAGCCCG
- 44.An enzyme that changes the shape of supercoiled DNA without changing its linking number is (pg 376 or 576)
- A.
Gyrase
- B.
Topoisomerase II
- C.
Helicase
- D.
Topoisomerase I
- 45.Which polymerase has the highest processivity?
- A.
DNA Polymerase III
- B.
DNA Polymerase gamma
- C.
DNA Polymerase delta
- 46.The genes for the enzymes needed int he synthetic pathway of a biomolecule usually are found int he form of
- A.
Gene families
- B.
An operon
- C.
Housekeeping genes
- D.
Oncogenes
- 47.The term "upstream" means (p 1019)
- A.
Any place int he DNA after the promoter site
- B.
Any place in the DNA at the noncoding region
- C.
A consensus sequence that goes from 3' to 5'
- D.
Any region in the DNA that is closer to the 5' end
- 48.Telomerase is an enzyme that (p 1008)
- A.
Decreases the size of the telomeres
- B.
Extends the 3' end of the telomeres lagging strand
- C.
It is not found in vertebrates
- D.
Uses a DNA primer to enxtend DNA
- 49.A strain of E.coli produces the same high level of beta-galactosidase regardless of concentration of lactose in the medium. This strain most likely contains a deltion mutation int he gene (Note: you may assume that deletion mutation causes normal function
- A.
Lac I
- B.
Lac 2
- C.
Gene coding for the gamma-subunit of RNA polymerase
- D.
Gene encoding the catabolite activator protein
- 50.Which statement is INCORRECT about RNA polymerase in E. coli?
- A.
It does not contain a 3' or 5' exonuclease activity
- B.
Its holoenzyme contains four different subunits organized as alpha beta beta prime, gamma
- C.
It synthesizes mRNA, tRNA, rRNA as well as the RNA primers during replication
- D.
It uses the nucleotides UTP, GTP, ATP, and CTP as substrates
- 51.Which statement is incorrect about a typical E. coli promoter?
- A.
It consists of approximately 60 bp of dsDNA
- B.
It is recognized and bound by the gamma subunit of RNA polymerase holoenzyme
- C.
The base sequences centered at -10 of various promoters are not identical but always differ by two or fewer bases form the consensus sequence
- D.
It contains a "GC rich" consensus sequence centered at -10 called the pribnow box
- 52.
- A.
Depurinated
- B.
Dephosphorylated
- C.
Annealed
- D.
Less active
- 53.In duplex DNA, how many hydrogen bonds does thymine use?
- A.
2
- B.
3
- C.
4
- D.
1
- 54.One of the following is used for protein synthesis:
- A.
ATP
- B.
UTP
- C.
CTT
- D.
GTP
- 55.The molecule that carries the pure genetic message in eukaryotes is:
- A.
Antisense DNA
- B.
MRNA
- C.
Sense DNA
- D.
HnRNA
- 56.If snake venon phosphodiesterase (3' - "a" cutter) cleaved the molecule above, what fragments would you expect as a result
- A.
PG, pATAC
- B.
PGp, ATAC
- C.
PGATA, pC
- D.
PGATAp, C
- 57.In dsDNA the direction of the strand is
- A.
Both are 5'-3'
- B.
One is 5'-3' and other is 3'-5'
- C.
Both are 3'-5'
- D.
None of the above
- 58.The nucleic acid that is unstable in ACID is
- A.
DNA
- B.
MRNA
- C.
RRNA
- D.
TRNA
- 59.The reason why DNA is stable in BASE and RNA is not is because
- A.
RNA is single stranded
- B.
DNA is more basic
- C.
DNA is complexed with proteins
- D.
RNA has a 2-OH group
- 60.In the Sanger's DNA sequencing method, what is the reason for the stop of the chain elongation?
- A.
The dideoxynucleotide triphosphate (DTP)
- B.
The primer strand
- C.
The template strand has been synthesized with stops in it
- D.
One of the dNTPs
- 61.Which of the following double-stranded DNAs may convert to a cruciform structure?
- A.
ATGCATGCATGCATGCACGTACGTACGTACG
- B.
ATATATATGCGCGCGCGCTATATATACGCGCGCGCG
- C.
CATTAAGCAGTGCTTAAGAGTAATTCGTCACGAATTCT
- D.
AAAAAAAAACCCCCCCCTTTTTTTTTGGGGGGGG
- 62.Which statement is INCORRECT about the structure of native E.coli chromosomal DNA?
- A.
The DNA is primarily in the B-helix
- B.
The DNA is circular and supercoiled
- C.
The DNA exists as a right handed double helix
- D.
The DNA is one large linear piece about 4000 kb in length
- 63.Which item of experimental evidence gives the most support to the conclusion that "Every PURINE BASE pairs with a PYRIMIDINE BASE"
- A.
% of A = % of G
- B.
% of C = % of T
- C.
% of PURINES = % of PYRIMIDINE
- D.
% of Percent Base Composition in any organism is the same in all cells of the organism and is characteristic of that
- 64.All are true of the DNA double helix EXCEPT:
- A.
The strands are parallel
- B.
The strands are held by hydrogen bonds
- C.
The strands are complementary
- D.
The strands dissociate with high Urea
- 65.In eukaryotes, a DNA is found in:
- A.
The nucleus, ribosomes, and mitochondria
- B.
The nucleus, mitochondria, and chloroplasts
- C.
The nucleus, and mitochondria
- D.
The nucleus
- 66.In the repair of DNA, the E.coli DNA polymerase involved performs which function in addition to its polymerase activity?
- A.
It recognizes the abnormality in the duplex DNA structure
- B.
It removes the damaged section of DNA with its 5'-3' exonuclease activity
- C.
It nicks DNA to provide a 3'-OH
- D.
It ligates the DNA after the repair synthesis
- 67.Why is a primer strand needed in DNA replication?
- A.
It insures the fidelity of the newly synthesized DNA strand
- B.
The DNA polymerases require a preexisting strand with a nucleotide having a 5'-OH
- C.
The DNA polymerases require a preexisting strand with a nucleotide having a 3'-OH
- D.
All of the above are correct
- 68.Which one of the following characteristics IS NOT associated with E. coli PRIMASE?
- A.
It is essential for DNA replication
- B.
It synthesizes the RNA primer in DNA replication
- C.
It is also a gyrase
- D.
It is a specific RNA polymerase
- 69.In the processing of the Okazaki fragments into a continuous DNA strand in E. coli, which of the following enzyme activity IS NOT required?
- A.
Polymerase I
- B.
Ligase
- C.
RNA-H
- D.
DNAse
- 70.Telomerase is found in humans in
- A.
Somatic cells
- B.
Tumor cells
- C.
Senescent cells
- D.
Only found in prokaryotes
- 71.The subunit involved in melting dsDNA in RNA polymerase is
- A.
α (alpha)
- B.
γ (gamma)
- C.
σ (sigma)
- D.
δ (delta)
- 72.TRANSCRIPTION is throught to generate
- A.
Positive supercoils BEHIND the transcription bubble
- B.
Positive supercoils IN FRONT of the transcription bubble
- C.
Negative supercoils IN FRONT of the transcription
- D.
A relaxed DNA during the transcription process
- 73.Since the HEPTAPEPTIDE repeats (in the carboxy terminal domain located in the large subunit of RNA Polymerase II) can be phosphorylated, the repeats must contain:
- A.
Serine
- B.
Aspartic Acid
- C.
Histidine
- D.
Tryptophan
- 74.The Pribnow box is located
- A.
At -10 from the ENHANCER ELEMENT
- B.
At -10 bp from the INITIATION SITE
- C.
At -35 bp from the OPERATOR
- D.
At -35 bp from STARTING CODON
- 75.The RNA Polymerase SLOWS down in
- A.
AT regions
- B.
Poly A regions
- C.
UA regions
- D.
GC regions
- 76.INCREASE in gene expression in response to a METABOLITE is called:
- A.
Induction
- B.
Repression
- C.
Co-Induction
- D.
Co-Repression
- 77.LEUCINE is coded by 6 different codons, this represents
- A.
Degeneracy
- B.
Synonymous codons
- C.
Unambiguous codons
- D.
All of the above
- 78.One of these codons is likely to code for NON-POLAR amino acid
- A.
GUU
- B.
GAC
- C.
GGG
- D.
GAA
- 79.T-RNA (Met) and t-RNA (fMet)
- A.
Can recognize the AUG codon
- B.
Are the same t-RNA but with different amino acids
- C.
Are used by eukaryotes and prokaryotes
- D.
None of the above
- 80.In eukaryotic translation
- A.
The t-RNA (Met) is used for INITIATION and ELONGATION
- B.
The t-RNA (Met) is used for INITIATION only
- C.
Is INITIATED with t-RNA (fMet)
- D.
There are two separate t-RNA (Met) used for INITIATION and ELONGATION
- 81.The oligonucleotide, AUGGp, has all these properties, EXCEPT
- A.
Composed of ribonucleotides
- B.
Contains a 3' phosphate
- C.
Composed of deoxyribonucleotides
- D.
Contains three phosphodiester bonds
- 82.An individual heterogeneous nuclear RNA (hnRNA)
- A.
Contains INTRON sequences not found in the final mature mRNA
- B.
Contains EXON sequences which are removed prior to translation
- C.
Encodes MORE THAN ONE protein
- D.
Can be found in the CYTOPLASM
- 83.The RNA molecules which are involved in PROCESSING the hnRNA are
- A.
MRNA
- B.
TRNA
- C.
RRNA
- D.
SnRNA
- 84.
- A.
TRNA contains numerous intramolecular HYDROGEN BONDS between bases
- B.
There are MORE DISTINCT tRNA molecules than there are rRNA molecules
- C.
RRNA are complexed to PROTEINS in the ribosome
- D.
The MOST ABUNDANT RNA molecule in the cell is mRNA
- 85.Which of the following IS NOT a characteristic for DNA synthesis?
- A.
DNA polymerase ADDS nucleotides in a 5'-3' direction
- B.
A PRIMER STRAND of DNA must contain a free 3'-OH end
- C.
The PRIMER STRAND of DNA DETERMINES which nucleotide are ADDED NEXT
- D.
The correct COMPLEMENTARY HYDROGEN BONDING between base pairs is the PRIMARY CHECK on the fidelity of the newly synthesized DNA
- 86.A DNA is found to exhibit a melting temperature of 75 C in 0.1 M NaCl. Under what experimental conditions would the Tm be INCREASED?
- A.
DECREASING the concentration of DNA
- B.
INCREASING the concentration of NaCl in the solution
- C.
ADDING 1% urea (an organic denaturant)
- D.
All of the above
- 87.A feature which is distinctive to Z-DNA is
- A.
A LEFT-HANDED helix
- B.
It has 12 BASES per turn
- C.
It is found IN VIVO
- D.
All of the above
- 88.The linking number of a highly SUPERCOILED plasmid can be readily changed WITHOUT producing a relaxed DNA by:
- A.
Changing the TEMPERATURE
- B.
INCREASING the salt concentration
- C.
The action of TOPOISOMERASE
- D.
The action of a NUCLEASE such as pancreatic DNAse
- 89.Which statement is INCORRECT about the STRUCTURE of native E. COLI chromosomal DNA?
- A.
The DNA is primarily in the BETA-helix
- B.
The DNA is CIRCULAR and SUPERCOILED
- C.
The DNA exists as a RIGHT-HANDED double helix
- D.
The DNA is one large LINEAR piece about 4000 kb in length
- 90.E. coli DNA POLYMERASE I has all of the following characteristics EXCEPT
- A.
A 5'-3' EXONUCLEASE activity on a SECOND subunit in the POLYMERASE
- B.
A 3'-5' EXONUCLEASE activity
- C.
A 5'-3' DNA POLYMERASE activity
- D.
MODEST processivity (20 nucleotides)
- 91.IN THE REPAIR of DNA, the E.coli DNA POLYMERASE involved performs which function IN ADDITION to its polymerase activity?
- A.
It RECOGNIZES the ABNORMALITY in the duplex DNA structure
- B.
It NICKS the DNA to provide a 3'-OH
- C.
It REMOVES the DAMAGED section of DNA with its 5'-3' EXONUCLEASE activity
- D.
It LIGATES the DNA after the REPAIR synthesis
- 92.The KLENOW fragment of E. Coli DNA Polymerase I can be used to ADD nucleotides to a DNA WITHOUT staggered ends, IF THE ENDS...
- A.
Are RECESSED with 5'-phosphates
- B.
Are RECESSED with 3'-OHs
- C.
Are EXTENDED with 5'-phosphates
- D.
Are EXTENDED with 3'-OHs
- 93.Which of the following IS NOT a characteristic of REPLICATION of the E.coli CIRCULAR chromosome?
- A.
Replication is BIDIRECTIONAL
- B.
It INITIATES at a unique position called oriC
- C.
TORSIONAL STRESS introduced in the duplex DNA is relieved by DNA GYRASE
- D.
The UNWINDING of the duplex DNA is driven by the TRANSLOCATION of the DNA Polymerase
- 94.E. coli REPLICATION on the LAGGING strand
- A.
Is primarily carried out by DNA Polymerase I
- B.
Is synthesized CONTINUOUSLY
- C.
This DNA strand is synthesized int he 3'-5' direction of the synthesis
- D.
Is initially synthesized as OKAZAKI FRAGMENTS
- 95.Which of the following characteristic IS NOT associated with E. coli PRIMASE
- A.
It synthesizes the RNA PRIMER in DNA replication
- B.
It is a SPECIFIC RNA polymerase
- C.
It is ESSENTIAL for DNA replication
- D.
It is also a GYRASE
- 96.The POLYMERASE IN EUKARYOTIC REPLICATION which plays a similar role as that of PROKARYOTIC'S Polymerase III is?
- A.
DNA Polymerase γ (gamma)
- B.
DNA Polymerase δ (delta)
- C.
DNA Polymerase σ (sigma)
- D.
DNA Polymerase α (alpha)
- 97.Which IS NOT a property of E. coli DNA Polymerase III?
- A.
It is responsible for incorporating MOST of the NUCLEOTIDES in the LAGGING strand
- B.
It synthesizes MOST of the LEADING strand PRIOR to aiding in the synthesis of the LAGGING strand
- C.
It contains a 3'-5' EXONUCLEASE activity
- D.
It synthesizes the LEADING strand and the LAGGING strand at the SAME TIME
- 98.Which statement is INCORRECT about E. coli DNA Polymerase I?
- A.
The cells contain MORE MOLECULES of DNA pol I than DNA pol III
- B.
DNA pol I is a SINGLE POLYPEPTIDE with THREE domains
- C.
DNA pol I is involved in the REPAIR of UV-damaged DNA
- D.
DNA pol I has a LARGER TURNOVER number than DNA pol III
- 99.Which E. coli ENZYME has the GREATEST FREQUENCY of incorporating the INCORRECT NUCLEOTIDE into is nucleic acid POLYMER?
- A.
RNA polymerase
- B.
DNA polymerase I
- C.
DNA polymerase III
- D.
KLENOW fragment from DNA polymerase I
- 100.DNA-DEPENDENT RNA polymerase acts on the DNA template in EUKARYOTIC CELLS in the SYNTHESIS of:
- A.
A 5'-3' hnRNA TRANSCRIPT as the RNA polymerase moves in the 3'-5' direction on the DNA template
- B.
A mature RNA transcript a the RNA polymerase moves in the 5'-3' direction
- C.
An RNA transcript, with the SIGMA subunit of polymerase DISSOCIATING after the initiation event
- D.
An RNA transcript, which is COMPLEMENTARY to the SENSE strand of the DNA, except for the REPLACEMENT of the uridines for the thymidines
- 101.In eukaryotes, there are many MORE PROTEINS than GENES. This can be explained by
- A.
Association of proteins
- B.
Multiple subunites
- C.
Alternative splicing
- D.
Mutation
- 102.If you found a DNA molecule containing URACYL, the most probably CAUSE for it would be:
- A.
A mutation
- B.
A MISTAKE by the polymerase
- C.
A cytosine DEAMINATION
- D.
A probably ISOLATED RNA
- 103.Pure DNA has an absorbance ratio of:
- A.
260/280 = 2.0
- B.
280/260 = 1.8
- C.
260/280 = 1.8
- D.
260/240 = 1.6
- 104.In the RELAXED "B" DNA, one of these group of numbers is CORRECT:
- A.
W=0, L=20, T=20
- B.
W=20, L=20, T=0
- C.
T=20, L=20, W=40
- D.
L=40, W=20, T=20
- 105.DOUBLE-stranded RNA is found in?
- A.
Ribosomes
- B.
T-RNA
- C.
MRNA
- D.
RNA is NEVER double-stranded
- 106.E. coli DNA polymerase I has all of the following characteristics EXCEPT:
- A.
A 3'-5' EXONUCLEASE activity
- B.
A 5'-3' DNA polymerase activity
- C.
A 5'-3' EXONUCLEASE activity ON A SECOND subunit in the polymerase
- D.
MODEST processivity (20 nucleotides)
- 107.The KLENOW fragment has the following activities
- A.
POLYMERASE and 3'-EXONUCLEASE
- B.
3' and 5' EXONUCLEASE
- C.
POLYMERASE AND 5'-EXONUCLEASE
- D.
3' and 5' EXONUCLEASE, plus POLYMERASE
- 108.The COMMON activities of DNA pol I and pol III are:
- A.
POLYMERASE, 5' and 3' EXONUCLEASE
- B.
POLYMERASE, 3' EXONUCLEASE
- C.
POLYMERASE, 5' EXONUCLEASE
- D.
POLYMERASE
- 109.The "PROOF-READER" activitiy of Pol I is its
- A.
POLYMERASE activity
- B.
5' EXONUCLEASE activity
- C.
3' EXONUCLEASE activity
- D.
ENDONUCLEASE activity
- 110.A HELICASE is characterized by:
- A.
CUTS the DNA and RELIEVES supercoiling
- B.
It is also a GYRASE
- C.
UNWINDS DNA without cutting it
- D.
Needs GTP for energy
- 111.The enzyme which REMOVES the RNA PRIMER from the OKAZAKI fragment is:
- A.
Pol III
- B.
KLENOW fragment
- C.
PRIMASE
- D.
Pol I
- 112.DNA pol III REPLICATES the LAGGING strand by using
- A.
A LOOP on the LAGGING strand
- B.
By READING in the 5'-3' direction
- C.
By using ONE enzyme per strand
- D.
By moving BACKWARDS
- 113.The following are part of DNA REPLICATION in E. coli, EXCEPT
- A.
OKAZAKI fragments
- B.
OriC
- C.
Ter LOCUS
- D.
The PROMOTER
- 114.The TUS protein is a type of
- A.
Gyrase
- B.
Helicase
- C.
Primase
- D.
CONTRAhelicase
- 115.This ENZYME carries ITS OWN PRIMER
- A.
REVERSE transcriptase
- B.
Telomerase
- C.
Prokaryotic pol III
- D.
Primase
- 116.A GENE is a DNA SEQUENCE that encodes for:
- A.
A protein
- B.
RRNA
- C.
T-RNA
- D.
All of the above
- 117.In EUKARYOTES, mRNA is made by
- A.
RNA Pol I
- B.
RNA Pol II
- C.
RNA Pol III
- D.
RNA Pol σ (sigma)
- 118.The SITE where RNA polymerase BINDS is the
- A.
Promoter
- B.
The starting site
- C.
The OriC site
- D.
The template
- 119.The CLOSE promoter COMPLEX is
- A.
LOOSER than the OPEN promoter COMPLEX
- B.
Form by RNA Pol CORE enzyme
- C.
TIGHTER than the OPEN promoter COMPLEX
- D.
None of the above
- 120.TRANSCRIPTION is finished by one of these subunits ***
- A.
Delta
- B.
Sigma
- C.
Alpha
- D.
Beta
- 121.A STRONG promoter is one that
- A.
Is GC rich
- B.
Is AT rich
- C.
Has a SEQUENCE closest to CONSENSUS
- D.
Has a WEAKLY bound OPEN complex
- 122.POSITIVE control of the LAC operon is ACHIEVED by:
- A.
BINDING of the REPRESSOR to the OPERATOR
- B.
BINDING of the INDUCER to the PROMOTER
- C.
DETACHING of the REPRESSOR from the OPERATOR
- D.
DETACHING of the INDUCER from the PROMOTER
- 123.In order to ACTIVATE the catabolite activator protein (CAP), it has to be
- A.
Phosphorylated
- B.
CAMP adenylated
- C.
Glycosilated
- D.
None of the above
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