Test
Biochem Final Homework
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Preguntas del test (56)
1Which of the following polymerases is responsible for lagging strand synthesis in eukaryotes?
- APol α
- BReverse transcriptase
- CPol ε
- DPol δ
2Which of the following proteins in the eukaryotic replication fork plays the same role as the β clamp in the prokaryotic replication for?
- ARPA
- BPCNA
- CMCM2-7
- DRFC
3Which of the following proteins is responsible for binding to oriC to initiate replication in E. coli?
- ADnaC
- BDnaB
- CDnaA
- DPrimase
4DNA replication in eukaryotes takes place during which phase of the cell cycle?
- AG1
- BS
- CG2
- DM
5Which of the following statements is FALSE concerning telomerase?
- AIt helps maintain chromosome length.
- BIt uses an RNA template to extend DNA at the end of chromosomes
- CIt synthesizes an RNA primer to facilitate DNA synthesis
- DIts activity is largely limited to undifferentiated embryonic stem cells, male germ cells, and activated lymphocytes.
6Which of the following statements is FALSE concerning the role of DNA damage in cancer?
- ASomatic mutations that result in decreased cell viability contribute to cancer development.
- BExposure to certain environmental factors can increase the number of somatic mutations.
- CSomatic mutations that alter regulation of cell division contribute to cancer development.
7Which of the following types of DNA damage is directly caused by UV radiation?
- ASubstitution mutation
- BAbasic site
- CCytosine deamination
- DThymine dimers
8Which nucleobase is most commonly affected by alkylating agents?
- AG
- BC
- CT
- DA
9In a eukaryotic cell, nucleotide substitutions take place during which stage?
- Atranscription
- BS phase
- Canaphase
- Dmitosis
10Mismatch repair in E. coli is dependent on
- Abase methylation within the parental DNA strand.
- Bbase phosphorylation within the newly synthesized DNA strand.
- Cbase methylation within the newly synthesized DNA strand.
- Dbase phosphorylation within the parental DNA strand.
11A common DNA mutation is caused by a hydrolysis reaction that results in a [blank_start]________[blank_end] that converts cytosine to [blank_start]________[blank_end] .
- Adeamination
- Bdecarboxylation
- Cdephosphorylation
- Dthyamine
- Euracil
- Fguanine
- Gadenine
12Rank the E.coli mismatch repair proteins in order with regard to their first association with a DNA lesion (first to third)
- AMutS, MutL, MutH
- BMutH, MutS, MutL
- CMutS, MutH, MutL
13Chymotrypsin is a serine protease, which helps to digest food by cleaving the peptide backbone of proteins. Which of these is not an amino acid that is present in the catalytic triad of the active site of chymotrypsin?
- Ahistamine
- Balanine
- Caspartic acid
- Dserine
14Which of these mutations is the most likely to eliminate the ability of chymotrypsin to perform its function? (Amino acids are represented by their three-letter code, with the residue number immediately following the name of the amino acid. The amino acid listed before the arrow is the original amino acid, and the amino acid listed after the arrow is the amino acid into which it has been mutated.)
- AHis57→Tyr
- BSer195→His
- CSer195→Thr
- DAsp102→Glu
15For chymotrypsin, which amino acid is involved in forming the oxyanion hole, but is not part of the catalytic triad?
- ASer 195
- BGlycolic 193
- CAsp 102
- DHis 57
16Trypsin, chymotrypsin, and elastase are all serine proteases that cleave after different amino acids. What is responsible for the substrate specificity?
- ADifferent amino acids involved in the catalytic triad
- BDifferent catalytic mechanisms
- CEach protease is made in a different cell type.
- DThe substrate binding pockets accommodate different amino acids.
17[blank_start]______[blank_end] are stable molecules that mimic a transition state and bind to the [blank_start]______[blank_end] of enzymes. The [blank_start]______[blank_end] affinity of these analogs for the enzymes supports the transition state theory because it is assumed that the similarly shaped transition state is energetically favorable.
- ATransition State Analogs
- BActive Sites
- CSubstrate
- DSubstrate
- EActive Site
- FFluctuating
- GHigh
- HLow
18During the allosteric regulation of the bacterial enzyme aspartate transcarbamoylase (ATCase), two different allosteric regulators affect the activity of the enzyme on its substrate aspartate. CTP (cytidine triphosphate) [blank_start]______[blank_end] ATCase activity, while ATP (adenosine triphosphate) [blank_start]______[blank_end] ATCase activity. In the absence of either of these allosteric regulators, the activity of ATCase is [blank_start]_____[blank_end] the activity of CTP- and ATP-activated ATCase.
- AStimulates
- BInhibits
- CDoes Not Alter
- DStimulates
- EInhibits
- FDoes Not Alter
- GLess Than
- HGreater Than
- IIn Between
- JEqual To
19Which of the following statements is FALSE concerning DNA mismatch repair in E. coli?
- AMutH has endonuclease activity.
- BMutS recognizes base pair mismatches.
- CThe non-methylated strand of DNA is used as the template for repair.
- DPol III resynthesizes the DNA that has been removed.
20Which of the following mutations is NOT corrected via base excision repair?
- AAbasic site
- BUracil
- CThymine dimer
- D8-hydroxyguanine
21Which of the following DNA repair mechanisms does NOT require a DNA template?
- ADouble-strand DNA repair via homologous recombination
- BSingle-strand DNA break repair via long repair gap filling
- CDouble-strand DNA repair via non-homologous end joining
- DSingle-strand DNA break repair via short repair gap filling
22During which stage of meiosis do sister chromatin undergo homologous recombination?
- AS
- BMeiosis 1
- CG2
- DG1
23Based on the figure below, cleavage followed by rejoining at which sites would lead to no recombination or loss of genetic information?
- A1 and 2
- B2 and 3
- C1 and 3
- D1 and 4
24In a eukaryotic cell, nucleotide substitutions take place during which stage?
- Atranscription
- Banaphase
- CS phase
- Dmitosis
25A common DNA mutation is caused by a hydrolysis reaction that results in a [blank_start]______[blank_end] that converts cytosine
to [blank_start]______[blank_end] .- AAdenine
- BUracil
- CGuanine
- Ddephosphorylation
- Edeamination
26Crossover occurs during [blank_start]______[blank_end].
- Aprophase 1
- Bprophase 2
- CS phase
- Danaphase
27Crossover occurs during the process(es) of [blank_start]______[blank_end].
- Ameiosis only
- Bmitosis only
- Cmeiosis and mitosis
28Which of the following RNAs is NOT involved in protein synthesis?
- ArRNA
- BtRNA
- CRNaseP
- DmRNA
29Which of the following is NOT a way that RNA is dynamic?
- ARNA undergoes rapid synthesis and degradation within the nucleus.
- BRNA tertiary structure can be altered by interactions with ligands.
- CTransient base pairing between RNA molecules can modulate protein synthesis.
- DRNA mutations are not corrected within cells.
30Which of the following RNAs is both used during protein synthesis and is NOT recycled?
- AtRNA
- BmRNA
- CrRNA
- DncRNA
31Which of the following statements is correct concerning eukaryotic mRNA?
- AEukaryotic mRNA is polycistronic.
- BEukaryotic mRNA is monocistronic.
- CTranscription and translation of eukaryotic mRNA is coupled.
- DEukaryotic mRNA does not undergo splicing to remove introns.
32Which protein is responsible for targeting RNA polymerase to promoters in bacteria?
- Aσ
- Bω
- Cα
- Dβ
33Which of the following RNAs is NOT involved in protein synthesis?
- ARNaseP
- BtRNA
- CrRNA
- DmRNA
34Which of the following is NOT a way that RNA is dynamic?
- ARNA mutations are not corrected within cells.
- BRNA undergoes rapid synthesis and degradation within the nucleus.
- CRNA tertiary structure can be altered by interactions with ligands.
- DTransient base pairing between RNA molecules can modulate protein synthesis.
35Which of the following RNAs is both used during protein synthesis and is NOT recycled?
- ArRNA
- BncRNA
- CtRNA
- DmRNA
36Which of the following statements is correct concerning eukaryotic mRNA?
- ATranscription and translation of eukaryotic mRNA is coupled.
- BEukaryotic mRNA is monocistronic.
- CEukaryotic mRNA is polycistronic.
- DEukaryotic mRNA does not undergo splicing to remove introns.
37Which protein is responsible for targeting RNA polymerase to promoters in bacteria?
- Aα
- Bβ
- Cω
- Dσ
38Which of the following is NOT an event that occurs during prokaryotic transcription?
- ATranscription termination can occur when Rho protein binds to a C-rich region of the transcript.
- BThe σ factor departs when the closed complex forms at the promoter.
- CTranscription termination can occur when a GC-rich stem loop followed by multiple uridines forms.
- DFormation of the open polymerase complex is associated with DNA unwinding.
39Which of the following is NOT a type of processing done to convert precursor mRNA to mature mRNA in eukaryotes?
- APolyadenylation
- B5′ capping
- CMethylation
- DSplicing
40Which of the modified bases in the figure below is 5-hydroxymethylcytosine?
- A7
- B2
- C8
- D4
41What is the role of σ factor in prokaryotic transcription?
- Ato ensure transcription begins in the correct location
- Bto signal for termination of transcription
- Cto promote elongation by RNA polymerase
- Dto stabilize the RNA polymerase complex
42Which mechanisms are similar in prokaryotic and eukaryotic transcription of mRNA?
- Arecruitment of RNA polymerase to DNA
- BRNA synthesis
- Ctranscription termination
- Dprocessing of mRNA
43Which of the following statements regarding the transcription and mRNA processing in eukaryotes is NOT correct?
- AHyperphosphorylation of the RNA polymerase II CTD regulates the interaction of mRNA processing enzymes with the newly transcribed regions of mRNA.
- BTranscription factors (TFIIA, TFIIB, TFIIE, TFIIH) assemble on RNA polymerase II after it binds to TFIID/TBP.
- CCapping of the mRNA 5' end occurs co-transcriptionally.
- DSplicing of the mRNA occurs co-transcriptionally.
44Which of the following RNAs provides the link directly between the DNA genetic code and the amino acids in proteins?
- AtRNA
- BmRNA
- CsiRNA
- DrRNA
45Which amino acid was coded by the first codon deciphered?
- APhe
- BGly
- CLys
- DPro
46How many of the 64 possible codons can be assigned to specific amino acids?
- A61
- B62
- C63
- D64
47Inosine in a tRNA can base pair to all EXCEPT which of the following nucleobases?
- AC
- BA
- CU
- DG
48Which of the following statements is correct concerning the wobble hypothesis and the wobble position?
- AInosine can be found in either the tRNA or the mRNA.
- BThe wobble position allows for a single tRNA to interact with multiple codons.
- CWobble interactions only occur when inosine is present.
- DInosine in the first or second position of a codon would have no effect on the resulting peptide.
49Which of the following statements is FALSE concerning codons in mRNA?
- AThe length of a codon needs to be three bases.
- BThe mitochondrial genome contains alternative tRNA genes.
- CAll codons are used at the same frequency in all organisms.
- DFor a particular sequence of RNA, three reading frames are possible.
50In the figure below, which structure is known as the acceptor stem?
- A1
- B2
- C7
- D5
51Which of the following statements is FALSE concerning tRNA synthetases?
- AThe tRNA synthetases use two proofreading steps to ensure accurate charging of tRNAs.
- BThe amino acid is ultimately linked to the 3′ OH of the terminal adenosine of the tRNA.
- CThere are two classes of aminoacyl-tRNA synthetases.
- DEach tRNA-amino acid codon combination has its own designated aminoacyl-tRNA synthetase.
52Which of the following components does NOT participate in translation initiation?
- ASmall ribosomal subunit
- BmRNA
- CtRNAThr
- DLarge ribosomal subunit
53How many binding sites are there in the ribosome for tRNA?
- A1
- B3
- C2
- D4
54Which of the following statements is FALSE concerning translation initiation in prokaryotes?
- AThe 70S ribosomal complex is made up of the 30S and the 50S subunits.
- BThree initiation factors (IFs) are necessary.
- CATP hydrolysis provides energy necessary for formation of the initiation complex.
- DThe ribosome binding site is known as the Shine-Dalgarno sequence.
55What is the energy required to undergo one cycle of translational elongation?
- A1 GTP
- B2ATP
- C1 ATP
- D2 GTP
56Which of the following is NOT a part of translational termination?
- ARelease factor recognition of stop codon in the mRNA
- BUncharged tRNA recognition of stop codon in the mRNA
- CGTP hydrolysis
- DRibosome subunit dissociation
Información
- Descripción
- Test sobre Biochem Final Homework, creado por A. N. el 11/12/2019.
- Autor
- A. N.
- Idioma
- English
- Visitas
- 18
- Valoración
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