BCH401G Final
What is the pH of an aqueous solution of a weak acid at a concentration of 1.0 M if the pKa is 6? A) 3 B) 4 C) 5 D) 6 E) 7
A) 3
If the coding (sense) strand of DNA is AAGGCTAT then what mRNA sequence will RNA polymerase generate? All sequences shown below are written from 5' to 3'. A) AAGGCUAU B) AAGGCTAT C) TTCCGATA D) UAUCGGAA E) AUAGCCUU
A) AAGGCUAU
If the tRNA anticodon arm sequence is CAG from 5' to 3' what is the complementary mRNA codon? A) CUG from 5' to 3'. B) CUG from 3' to 5'. C) CTG from 3' to 5'. D) CTG from 5' to 3'. E) GAC from 5' to 3'.
A) CUG from 5' to 3'.
Reduced activity of bird, reptile, or amphibian DNA photolyase would most likely result in which of the following outcomes? A) Increased dimerization of adjacent pyrimidines B) Decreased deamination of cytosine C) Increased deamination of cytosine D) Decreased dimerization of adjacent pyrimidines E) Increased fidelity of DNA polymerase
A) Increased dimerization of adjacent pyrimidines
The mRNA 5' cap is added through a series of enzyme-catalyzed reactions. The first is ___________ followed by transfer of GMP, and finally _____________. A) dephosphorylation; methylation B) transfer of AMP; methylation C) methylation; dephosphorylation D) dephosphorylation; another GMP transfer E) methylation; another GMP transfer
A) dephosphorylation; methylation
44. A cDNA library will contain DNA corresponding to: A) housekeeping genes. B) tRNA. C) all of the DNA in the organisms genome. D) introns. E) miRNA.
A) housekeeping genes.
Select the answer that correctly labels the diagram of B-DNA shown below. A. 1 = major groove, 2 = 10.4 nucleic acid residues/turn, 3 = sugar-phosphate backbone B. 1 = major groove, 2 = 3.6 nucleic acid residues/turn, 3 = sugar-phosphate backbone C. 1 = minor groove, 2 = 3.6 nucleic acid residues/turn, 3 = sugar-base backbone D. 1 = major groove, 2 = 10.4 nucleic acid residues/turn, 3 = nucleotide base pair
A. 1 = major groove, 2 = 10.4 nucleic acid residues/turn, 3 = sugar-phosphate backbone
Which of the following is TRUE concerning telomeres? ANSWERS 1. Rich in guanine A. 1, 2 2. Highly susceptible to exonucleases B. 2, 3 3. Are lengthened during DNA replication C. 3, 4 4. Telomerase can extend them in all cells D. 4, 5 5. Located at the center of chromosomes E. 2, 4
A. 1, 2
The genetic code is: 1. A combination of 64 codons. 2. Overlapping. 3. Degenerate. 4. Lacking in directionality. 5. Read in the 3' to 5' direction. A. 1, 3 B. 2, 3 C. 3, 4 D. 1, 5 E. 2, 4
A. 1, 3
Identify the compound shown at the right. A. 2'-deoxyadenosine 5'-monophosphate B. 2'-deoxythymidine 5'-monophosphate C. 2'-thymidine 5'-monophosphate D. 2'-deoxycytidine 5'-monophosphate E. 2'-deoxyguanosine 5'-monophosphate
A. 2'-deoxyadenosine 5'-monophosphate
What is the correct order of events during DNA chain elongation? Answers: 1- Hydrolysis of pyrophosphate & phosphodiester bond formation 2- Base pairing & hydrogen bonding 3- 3'-hydroxyl group attacks the a-phosphorous atom A. 2, 3, 1 B. 3, 1, 2 C. 1, 3, 2 D. 3, 2, 1 E.2, 1, 3
A. 2, 3, 1
DNA polymerase requires a primer with a free _________. A. 3'-OH B. 5'-OH C. 3'-PO4 D. 2'-PO4 E. 5'-PO4
A. 3'-OH
Put the following events of RNA polymerization in the correct order. 1 - RNA pol shifts towards the 3' end of the newly made RNA 2 - phosphodiester forms and pyrophosphate is released 3 - A RTP correctly pairs with a NTP on the DNA template 4 - nucleophilic attack by the 3'OH on the a-phosphorus of the incoming RTP Answers A. 3, 4, 2, 1 B. 2, 1, 3, 4 C. 3, 2, 4, 1 D. 1, 2, 4, 3 E. 3, 4, 1, 2
A. 3, 4, 2, 1
Put the following events in order to achieve a successful cloning experiment. 1 - Identify E. coli containing recombinant DNA 2 - transform DNA into E. coli 3 - cleave DNA with restriction enzymes 4 - ligate DNA pieces 5 - prepare plasmid and insert DNA A. 5, 3, 4, 2, 1 B. 5, 4, 3, 1, 2 C. 3, 4, 2, 1, 5 D. 3, 2, 5, 4, 1 E. 5, 4, 3, 2, 1
A. 5, 3, 4, 2, 1
Which of the following is TRUE if there is increased levels of histone acetylation. A. Acetylation reduces the affinity of histones for DNA. B. Increased positive charge of the histones, "tightening" interaction with DNA. C. Histone deacetylases (HDACS) are active in this region of DNA. D. Histone acetylases (HATs) are active in this region of mRNA. E. Transcription factors are less likely to bind to a promoter in this region.
A. Acetylation reduces the affinity of histones for DNA.
Which enzyme in the CITRIC ACID CYCLE does NOT generate a reduced coenzyme or ATP? A. Aconitase B. Isocitrate dehydrogenase C. Acetyl CoA carboxylase D. Malate dehydrogenase E. Succinyl CoA synthase
A. Aconitase
When a cytosine is deaminated to uracil, which of the following responses occurs first during DNA repair? A. AlkA glycosylase hydrolyzes the glycosidic bond. B. DNA pol I fills the gap. C. DNA ligase seals the nick. D. UvrABC fills the gap and seals the nick. E. AP endonuclease cleaves the sugar-phosphate backbone.
A. AlkA glycosylase hydrolyzes the glycosidic bond.
When a cytosine is deaminated to uracil, which of the following responses occurs first during repair? A. AlkA glycosylase hydrolyzes the glycosidic bond. B. DNA pol I fills the gap. C. DNA ligase seals the nick. D. UvrABC fills the gap and seals the nick. E. An endonuclease cleaves the sugar-phosphate backbone.
A. AlkA glycosylase hydrolyzes the glycosidic bond.
The conservative model of replication stated that: A. Both parental DNA strands stay together after replication. B. DNA double helix contains one parental and one daughter strand after replication. C. Parental and daughter DNA are interspersed in both strands after replication. D. DNA is conserved in the cytoplasm and nucleus. E. DNA is a double helix with hydrogen bonded-bases in the center of the helix.
A. Both parental DNA strands stay together after replication.
Which of the below would be the strongest eukaryotic RNA pol II promoter? A. CAATCTATAAA B. TTATATATAAA C. CAATTGTGGG D. TATTTACAAT E. CACACATATA
A. CAATCTATAAA
In the results from Meselson and Stahl (to the right), the first generation results eliminate which model of DNA replication as being correct? A. Conservative model B. Semi-conservative model C. Dispersive model D. Progressive model E. The results do not eliminate any of the models
A. Conservative model
In the Meselson & Stahl experiment, _________________ and ______________ were utilized to separate the N14 and N15 labeled DNA. A. Density gradients; ultracentrifugation B. E. coli; PCR C. Restriction enzymes; DNA electrophoresis D. Sanger sequencing; cDNA library E. Gel filtration chromatography; X-ray film
A. Density gradients; ultracentrifugation
Which of the following statements is TRUE concerning stem cells? A. Embryonic stem cells are derived from a blastocyst. B. Mutipotency is the ability to develop into any cell type. C. A blastocyst is a 25-day old embryo. D. Adult stem cells are naturally pluripotent. Current treatment for leukemia utilizes limbal stem cell therapy
A. Embryonic stem cells are derived from a blastocyst.
Cytidine triphosphate is formed by the amination of Uridine triphosphate. In this reaction, ______________provides the amino group. A. Glutamine B. Glutamate C. Aspartate D. Ammonium ion E. Glycine
A. Glutamine
Which molecule initiates a signal transduction pathway by binding to a receptor tyrosine kinase at the plasma membrane which then promotes synthesis of the second messenger phosphatidylinositol 3,4,5-trisphosphate (PIP3) an activator of the PDK1 protein kinase? A. Insulin B. Glucagon C. Epinephrine D. Calcium E. Diacylglycerol
A. Insulin
Which lipoprotein results in a high level of serum cholesterol when its receptor on liver cells is defective? Such a defect is found in people with hypercholesterolemia. A. LDL B. VLDL C. HDL D. Chylomicrons E. IDL
A. LDL
Which of the glycolytic enzymes listed below is highly regulated? A. Phosphofructokinase-1 B. Glucose 6-phosphate isomerase C. Aldolase D. Triose Phosphate Isomerase E. Glucose 6-phosphate dehydrogenase
A. Phosphofructokinase-1
A mutation in the E. coli gene coding for Sigma subunits would MOST LIKELY result in: A. RNA polymerase binding non-specifically to DNA. B. RNA polymerase binding too tightly to transcription termination sites. C. increased mutations due to decreased recombination. D. increased mutations due to decreased mis-match repair. E. increased rate of transcription.
A. RNA polymerase binding non-specifically to DNA.
Reverse transcriptase is also referred to as a: A. RNA-dependent DNA polymerase B. RNA-dependent RNA polymerase C. DNA-dependent RNA polymerase D. DNA-dependent DNA polymerase E. mRNA-dependent rRNA polymerase
A. RNA-dependent DNA polymerase
Which statement BEST describes ion-exchange chromatography? A. Separates proteins based on charge B. Separates proteins based on size C. Separates proteins based on hydrophobicity D. Separates proteins by binding a specific site on the protein E. Separates proteins based on charge and size
A. Separates proteins based on charge
Which of the following is CORRECT regarding ribosomes? A. They bind mRNA, tRNA and the growing peptide chain. B. They are composed of multiple proteins and DNA. C. In eukaryotes, ribosomes bind mRNA as it is generated. D. In E. coli, the three major subunits are 10S, 90 S, and 100S. E.The small ribosomal subunit only participates in termination.
A. They bind mRNA, tRNA and the growing peptide chain.
Which answer describes a feature of membrane lipids that is TRUE? A. They can move rapidly in the 2-dimensional plane of a membrane leaflet B. The two leaflets of a membrane have a very similar lipid composition C. They flip rapidly from one leaflet of a membrane to the other leaflet D. Longer chain length fatty acids lower the melting temperature of a membrane E. Cholesterol is only found in one but not both leaflets of a membrane
A. They can move rapidly in the 2-dimensional plane of a membrane leaflet
. In nature (i.e. outside the lab), restriction enzymes are utilized by ________ to degrade ________ DNA? A. bacteria; phage B. phage; bacterial C. mammals; viral D. mammals; bacterial E. plants; bacterial
A. bacteria; phage
How does allolactose impact the lac operon in E. coli? A. binds to the lac repressor & increases operon transcription. B. binds to the lac repressor & decreases operon transcription. C. binds the lac operator & increases operon transcription. D. binds the lac operon promoter & increases operon transcription. E. binds the lac operon promoter & decreases operon transcription.
A. binds to the lac repressor & increases operon transcription.
What does allolactose do in E. coli cells? A. binds to the lac repressor & increases transcription of the lac operon. B. binds to the lac repressor & decreases transcription of the lac operon. C. degrades the lac repressor & decreases transcription of the lac operon. D. binds the lac operon promoter & increases transcription of the lac operon. binds the lac operon promoter & decreases transcription of the lac operon
A. binds to the lac repressor & increases transcription of the lac operon.
Single-stranded DNA is generated from double-stranded DNA during the step of a PCR, and the newly synthesized strand of DNA is generated during the step. A. denaturation, extension B. annealing, extension C. extension, annealing D. denaturation, annealing E. extension, denaturation
A. denaturation, extension
Eukaryotic mRNA is modified at the 5' end by ____________ and at the 3' end by ____________. A. guanylyl transferase; polyadenylation B. small nuclear riboncleoprotein complexes; polyuracilation C. polyuracilation; polyadenylation D. polyadenylation; polyuracilation E. polyuracilation; small nuclear riboncleoprotein complexes
A. guanylyl transferase; polyadenylation
When RNA polymerase binds DNA, ________ subunits are key for promoter recognition so that the _______ subunits can catalyze polymerization. A. sigma; beta B. beta; sigma C. sigma; alpha D. alpha; sigma E. sigma; omega
A. sigma; beta
Nuclear hormone receptors are activated when they bind _________ and then they bind ______________ to regulate transcription. A. small molecules; specific regions of DNA B. small molecules; random regions of DNA C. specific regions of DNA; small molecules D. random regions of DNA; small molecules E. random regions of DNA; specific regions of DNA.
A. small molecules; specific regions of DNA
The sequence to the right is MOST LIKELY: A. the 3' end of a tRNA. B. the 5' end of a tRNA. C. a DNA sequence. D. a transcriptional start site. E. a transcriptional stop site.
A. the 3' end of a tRNA.
47. If you are using a plasmid that is ampr then the E. coli are expressing the ___________ protein. A. β-Lactamase B. ampicillinase C. Neomycin phosphotransferase I D. lacZ E. β-Galactosidase
A. β-Lactamase
The difference between deoxynucleotides and dideoxynucleotides is at the: A) 3 position of their bases. B) 3' position of their sugars. C) 2 position of their bases. D) 2' position of their sugars. E) 4 position of their bases.
B) 3' position of their sugars.
Ribosomes move in the ____________ direction on an mRNA and the resulting proteins are made starting with their _______________. A) 5' to 3'; carboxy terminus B) 5' to 3'; amino terminus C) 3' to 5'; carboxy terminus D) 3' to 5'; amino terminus E) 3' to 5'; 3' to 5'
B) 5' to 3'; amino terminus
If the tRNA anticodon arm sequence is GAC from 5' to 3' what is the corresponding sequence in mRNA? A) GUC from 3' to 5'. B) GUC from 5' to 3'. C) GTC from 3' to 5'. D) GTC from 5' to 3'. E) GAC from 5' to 3'.
B) GUC from 5' to 3'.
46. Which of the following statements about recombinant DNA is TRUE? A) It can only be generated in the laboratory using restriction enzymes. B) It can be found in nature. C) Is often hypermethylated. D) It lacks key replication enzymes, so it does not replicate.
B) It can be found in nature.
Which result is MOST LIKELY if the -10 position of an E. coli gene were TATAAT? A) It is likely a weakly expressed gene. B) It will be transcribed at a high rate. C) It will be transcribed at a low rate. D) The gene possesses a weak promoter. E) DNA pol III is its likely polymerase.
B) It will be transcribed at a high rate.
Which statement about the genetic code is CORRECT? A) The code can be read in either direction. B) The code is non-overlapping. C) Each codon specifies more than one amino acid. D) One amino acid has only one codon that specifies for this amino acid. E) GAA is a termination codon
B) The code is non-overlapping.
Which of the statements listed below are TRUE regarding DNA replication? 1. DNA pol I possesses 5' to 3' exonuclease activity. Answers 2. DNA pol II can generate DNA de novo, i.e. without a primer. A. 1, 2 3. (DNA)n + dNTPs (DNA)n+1 + PPi. B. 1, 3 4. DNA pol III removes the RNA primer. C. 3, 4 5. The a-subunit of DNA pol surrounds DNA. D. 4, 5 E. 2, 5
B. 1, 3
The equivalent of ___________ molecule(s) are consumed in the synthesis of each amino-acyl-tRNA. A. 1 GTP B. 2 ATP C. 2 GTP D. 3 ATP E. 3 GTP
B. 2 ATP
The genetic code is: ANSWERS 1. Composed of 64 codons that each specifies for an amino acid. A. 1, 2 2. Non-overlapping. B. 2, 3 3. Degenerate. C. 3, 4 4. Non-directional. D. 4, 5 5. Typically written in the 3' to 5' direction. E. 1, 5
B. 2, 3
What is the order of events to remove and replace Okazaki fragments? 1. DNA pol I polymerizes DNA strand. ANSWERS 2. RNA ligase seals adjacent nucleotides. A. 5, 2, 1 3. DNA pol I removes the RNA primer. B. 3, 1, 5 4. DNA pol III polymerizes DNA strand. C. 2, 3, 4 5. DNA ligase seals adjacent DNA fragments. D. 4, 3, 2 E. 3, 4, 1
B. 3, 1, 5
What is the pH of a weak acid solution at a concentration of 1.0 M if the pKa is 8? A. 3 B. 4 C. 5 D. 6 E. 7
B. 4
In DNA pyrosequencing, the enzyme that converts PPi to ATP is _____________. A. luciferase B. ATP sulfurylase C. apyrase D. pyrophosphatase E. DNA polymerase
B. ATP sulfurylase
Fatty acid breakdown (beta-oxidation) begins in the cytosol where the enzyme called ______________ prepares fatty acids for entry into mitochondria. A. Acetyl CoA carboxylase B. Acyl-CoA synthetase C. Pyruvate dehydrogenase D. Acyl carrier protein E. Malonyl CoA carboxylase
B. Acyl-CoA synthetase
Which compound or class of compounds is excreted by the pancreas into the intestine to promote digestion and uptake of LIPIDS for metabolism in mammals? A. Nucleases B. Bile salts C. Zymogens D. Hydrochloric acid E. Insulin
B. Bile salts
Which of the following statements about tRNA is CORRECT? A. The anticodon loop hydrogen-bonds with RNA polymerase II. B. CCA is attached to the 3' end. C. The 3' end is the site of amino acid attachment. D. Every cell contains only 18 types of tRNA. E. Inosine is not found in tRNA.
B. CCA is attached to the 3' end. C. The 3' end is the site of amino acid attachment.
DNA synthesis depends on RNA synthesis because: A. DNA polymerase requires rRNA for its activity. B. DNA synthesis requires a RNA primer to initiate polymerization. C. a tRNA is a key component of the replication machinery. D. mRNA is needed as a template. E. an RNA catalyst generates phosphodiester bonds between nucleotides.
B. DNA synthesis requires a RNA primer to initiate polymerization.
A mutation in the gene encoding for topoisomerase that decreases its activity would most likely result in which of the following? A. Decreased breaking of DNA double helix hydrogen bonding. B. Decreased unwinding of supercoiled DNA. C. Increased exonuclease digestion of mRNA. D. Inefficient capping of mRNA. E. Mutations in the RNA primer.
B. Decreased unwinding of supercoiled DNA.
Which of the following correctly positions the aminoacyl-tRNA into the ribosome A site? A. Peptidyl transferase B. EF-Tu-GTP C. rRNA of the ribosome D. initiator tRNA E. N-formylmethionyl-tRNA
B. EF-Tu-GTP
The core of the protein at the right is made up of a pair of β sheets, each built of two antiparallel β strands. Which of the following is the MOST LIKELY amino acid in the interface of the two β sheets? A. D B. F C. K D. Q E. T
B. F
During times when muscles and liver contain a very low concentration of glucose, which compound listed below would be the primary source of carbon atoms to drive gluconeogenesis? A. Serine B. Glycerol C. Palmitic acid D. Leucine E. Palmitoyl-CoA
B. Glycerol
Which signaling pathway contains phosphatidylinositol 3,4,5-trisphosphate (PIP3)? A. Protein kinase C B. Insulin C. All pathways with a G-protein (GTPase) D. Protein kinase A E. Leptin
B. Insulin
Which of the following is TRUE regarding RNA polymerase? A. It catalyzes nucleotide extension faster than DNA pol. B. It forms phosphodiester bonds in the 5' to 3' direction. C. It possesses better proofreading than DNA pol. D. It can generate RNA de novo without a template strand. E. It requires a free 3'-hydroxyl.
B. It forms phosphodiester bonds in the 5' to 3' direction
Which lipid is diagrammed at the right? A. Cholesterol B. Phosphatidic acid C. Arachidonic acid D. Phosphatidylcholine E. Phosphatidylinositol
B. Phosphatidic acid
Which statement is TRUE concerning eukaryotic and bacterial transcription? A. They have approximately equal complexity of transcriptional regulation. B. RNA is more highly processed in eukaryotes than in bacteria. C. They both produce RNA in the nucleus. D. Eukaryotic RNA pol is a multi-subunit complex and bacterial RNA pol is a single protein. E. Coupled transcription-translation is common in both.
B. RNA is more highly processed in eukaryotes than in bacteria.
Which of the following statements about aminoacyl-tRNA synthetase is CORRECT? A. Each cell has only one. B. Some have proofreading activity. C. It performs engergetically inexpensive reactions. D. It generates 3 products: aminoacyl adenylate, aminoacyl tRNA, and peptide bonds. E. It adds CCA to the 5' end of every tRNA.
B. Some have proofreading activity.
Which coenzyme participates in the transfer of one carbon unit? A. Vitamin A B. Tetrahydrofolate C. CoA D. FAD E. Pyridoxal 5' Phosphate
B. Tetrahydrofolate
Gout is induced by a high level of urate in the blood stream. Allopurinol is used to treat gout because allopurinol is an inhibitor of the enzyme ______________ and prevents the formation of uric acid from precursor purines. A. Xanthine hydrolase B. Xanthine oxidase C. Hypoxanthine-guanine phosphoribosyltransferase D. Thymidylate synthase E. Dihydrofolate reductase
B. Xanthine oxidase
Tamoxifen is used to treat cancer because it: A. prevents a corepressor from binding the promoter. B. prevents a coactivator from binding the estrogen receptor. C. allows a corepressor to bind the promoter. D. allows a coactivator to bind the estrogen receptor. E. prevents the estrogen receptor from binding DNA.
B. prevents a coactivator from binding the estrogen receptor.
What is a major function of the DNA pol III β-subunit? A. DNA repair B. processivity C. termination of replication D. directionality (i.e. 5' to 3' movement) E. removal of RNA primers
B. processivity
In order to generate unique sticky ends for your insert and plasmid DNAs that can then be ligated together, you need to utilize ____________. A. one restriction endonuclease B. two restriction endonucleases C. five endoculeases D. two exonucleases E. four exonucleases
B. two restriction endonucleases
RNA polymerase catalyzes phosphodiester bond formation in the ___________ direction while the template strand is copied in the ____________ direction. A) 3' to 5' & 3' to 5' B) 5' to 3' & 5' to 3' C) 5' to 3' & 3' to 5' D) 3' to 5' & 5' to 3' E) the directions cannot be determined without more information
C) 5' to 3' & 3' to 5'
_________ removes the RNA primer of Okazaki fragments and ________ synthesizes the new DNA strand to replace the RNA primer: A) DNA pol III; DNA pol I B) Helicase; gyrase C) DNA pol I; DNA pol I D) DNA pol III; DNA pol III E) DNA pol I; DNA pol III
C) DNA pol I; DNA pol I
Which statement about protein folding is TRUE? A) Non-polar residues cluster on the outside of the protein. B) Disulfide bonds are required for proteins to fold properly. C) The free energy of most correctly folded proteins is at the global minimum. D) Protein folding occurs by a single defined pathway. E) Protein folding is an enthalpy-driven process.
C) The free energy of most correctly folded proteins is at the global minimum.
If the replication fork is moving from right to left (indicated by the arrow), which of the following is TRUE? A) The leading strand is synthesized left to right in the 3' to 5' direction. B) The lagging strand is synthesized right to left in the 3' to 5' direction. C) The lagging strand is synthesized left to right in the 5' to 3' direction. D) The lagging strand is synthesized right to left in the 5' to 3' direction. E) The leading strand is synthesized left to right in the 5' to 3' direction.
C) The lagging strand is synthesized left to right in the 5' to 3' direction.
Which type of eukaryotic RNA has the shortest half-life? A) charged tRNA B) rRNA C) mRNA D) non-charged tRNA E) dRNA
C) mRNA
After a ribonucleoside triphosphate pairs with the next unpaired nucleotide on the DNA template strand, RNA polymerase catalyzes a ________________ by the ____________ on the innermost phosphoryl group of the incoming ribonucleoside. A) nucleophilic attack, 5'-hydroxyl group B) nucleophilic attack, 2'-hydroxyl group C) nucleophilic attack, 3'-hydroxyl group D) hydrolysis, 3'-phosphate group E) hydrolysis, 5'-phosphate group
C) nucleophilic attack, 3'-hydroxyl group
Which answer BEST describes the meaning of KM in Michaelis-Menten kinetics? A) the equilibrium constant for the reaction. B) the maximum rate of the reaction. C) the substrate concentration that gives 1/2 maximum reaction rate. D) the rate of product formation. E) the rate of ES complex formation.
C) the substrate concentration that gives 1/2 maximum reaction rate.
Which of the techniques and reagents listed below were used by Meselson and Stahl in the experiment that we discussed? 1. N14 and N15 2. Ultracentrifugation 3. PCR 4. Southern blotting 5. E. coli A. 1, 2, 3 B. 2, 3, 4 C. 1, 2, 5 D. 1, 2, 4 e. 2, 3, 5
C. 1, 2, 5
Which of the follow are CORRECT concerning E. coli transcription termination? ANSWERS 1. RNA hairpins trigger termination. A. 1, 2 2. Transcription complexes disassemble at the 3' end of genes. B. 2, 4 3. Rho proteins bind RNA polymerase to trigger termination. C. 1, 4 4. Rho proteins bind ssRNA chain to trigger termination. D. 3, 5 5. The TATA box dictates the type of termination.
C. 1, 4
Which of the following statements is correct for hemoglobin and oxygen transport? A. O2 binds to the proximal histidine residue of the globin chain. B. Bonding of carbon dioxide to hemoglobin molecules increases O2 binding. C. 2,3-bisphosphoglycerate preferentially binds to deoxyhemoglobin and stabilizes it. D. The binding of each O2 molecule to hemoglobin decreases its affinity for the next O2 molecule. E. O2 binding causes hemoglobin to unfold.
C. 2,3-bisphosphoglycerate preferentially binds to deoxyhemoglobin and stabilizes it.
Which compound is used by liver cells to make ketone bodies when glucose is not available but the brain and other tissues need to make ATP? A. Fumarate B. Oxaloacetate C. Acetyl-CoA D. Acetone E. Acetoacetate
C. Acetyl-CoA
DNA replication in prokaryotes: A. Begins at the operon and proceeds in a complete circle to the termination site B. Begins at the operon and proceeds bidirectionally to the termination site. C. Begins at the oriC and proceeds bidirectionally to the termination site. D. Begins at the oriC and proceeds in a complete circle to the termination site. E. Begins at one of many start sites and each chromosome is replicated at the same time
C. Begins at the oriC and proceeds bidirectionally to the termination site.
A loss of function mutation in a cell's tRNA nucleotidyl transferase gene would MOST LIKELY result in which of the following? A. Decreased activity of the exonuclease that removes the tRNA 5' leader. B. Increased activity of the exonuclease that removes the tRNA 5' leader. C. Decreased addition of amino acids to tRNAs. D. Addition of multiple amino acids to a single tRNA. E. Abolished excision of tRNA introns by the spliceosome.
C. Decreased addition of amino acids to tRNAs.
Where are glycoproteins with N-linked sugars made in cells, and what type of amino acid(s) are the sugars attached to? A. ER, serine and arginine B. Golgi apparatus, serine and threonine C. ER, asparagine D. Golgi apparatus, asparagine E. Cytosol, serine
C. ER, asparagine
Which lipoprotein is the main transporter of cholesterol from peripheral tissues to the liver? A. LDL B. VLDL C. HDL D. Chylomicrons E. IDL
C. HDL
In the active methyl cycle, ______________ is generated and re-used to form Methionine. A. Glutamine B. Formyl-tetrahydrofolate C. Homocysteine D. Cysteine E. Glycine
C. Homocysteine
Which statement BEST describes what an uncompetitive inhibitor does? A. It binds at several different sites on an enzyme B. It binds reversibly at the active site C. It binds only to the ES complex D. It lowers the characteristic Vmax of the enzyme E. Covalently binds to the active site
C. It binds only to the ES complex
Which answer is most likely if the -10 position of an E. coli gene is GCGCCG? A. It is likely a highly expressed housekeeping gene. B. It will be transcribed at a high rate. C. It will be transcribed at a low rate. D. The gene possesses a strong promoter. E. DNA pol III is its likely polymerase.
C. It will be transcribed at a low rate.
To which enzyme class does orotidylate decarboxylase belong? A. Ligase B. Oxidoreductase C. Lyase D. Isomerase E. Transferase
C. Lyase
The dispersive model of replication stated that: A. Both parental DNA strands stay together after replication. B. The DNA double helix contains one parental and one daughter strand after replication. C. Parental and daughter DNA are interspersed in both strands after replication. D. DNA is dispersed in the cytoplasm and nucleus. E. The DNA double helix is dispersed with hydrogen bonded-bases in the center of the helix.
C. Parental and daughter DNA are interspersed in both strands after replication.
Which of the following is a biologically known exception to the Central Dogma? A. DNA transcribed into mRNA. B. mRNA translated into protein. C. Prions generating prions. D. DNA translated into protein. E. Protein reverse translated into mRNA.
C. Prions generating prions.
Which enzyme is specific to the gluconeogenic pathway? A. Enolase B. Aldolase C. Pyruvate carboxylase D. Glucose 6-phosphate isomerase E. Triose phosphate isomerase
C. Pyruvate carboxylase
Which glycolytic enzyme besides phosphofructokinase-1 is highly regulated? A. Aldolase B. Glucose 6-phosphate isomerase C. Pyruvate kinase D. Enolase E. Glucose 6-phosphate dehydrogenase
C. Pyruvate kinase
When does eukaryotic DNA replication occur? A. anaphase of meiosis B. G1 phase C. S phase D. G2 phase E. M phase
C. S phase
The _____________ is a key nucleotide sequence for mRNA translation in the untranslated region (UTR). A. -35 region B. TATA box C. Shine-Dalgarno sequence D. DPE promoter E. CAT box
C. Shine-Dalgarno sequence
Biochemical hybridization methods that analyze DNA are called __________ and those analyzing proteins are called _______________? A. Western blots; Southern blots B. Western blots; Northern blots C. Southern blots; Western blots D. Southern blots; Northern blots E. Northern blots; Southern blots
C. Southern blots; Western blots
Enzymes catalyze reactions by: A. Increasing the free energy of activation B. Releasing product quickly C. Stabilizing the transition state D. Changing the equilibrium constant for the reaction E. Decreasing the free energy of the enzyme-substrate complex
C. Stabilizing the transition state
Which statement about Okazaki fragments is CORRECT? A. Multiple Okazaki fragments make up the leading strand. B. They are uniquely synthesized in the 3' to 5' direction. C. They are synthesized 5' to 3' in the opposite direction as the replication fork. D. Okazaki fragment is the name of the RNA primers generated during DNA replication. E. Adjacent Okazaki fragments are ligated by DNA pol I.
C. They are synthesized 5' to 3' in the opposite direction as the replication fork.
Which of the small nuclear RNAs in the spliceosome are responsible for catalyzing the transesterification reaction? A. U1 and U2 B. U1 and U3 C. U2 and U6 D. U4 and U5 E. U5 and U6
C. U2 and U6
45. You perform a recombinant DNA experiment (i.e. subcloning), but you forget to cut the vector with restriction enzymes. You then transform the E. coli cells and plate them on the appropriate antibiotic plate. When you analyze the plate the next day what is the most likely outcome? A. Your plate will have no colonies on it. B. Your plate will be covered with bacterial colonies all containing just the insert. C. Your plate will be covered with bacterial colonies all containing just the vector. D. Your plate will have a few colonies and all will contain the vector and insert. E. Your plate will be covered with yeast colonies.
C. Your plate will be covered with bacterial colonies all containing just the vector.
A major difference between traditional PCR and QuickChange PCR is the: A. amount of DNA template. B. type of selection plate for the bacteria. C. amount of DNA amplification. D. length of the primers. E. type of thermocycler.
C. amount of DNA amplification.
In DNA pyrosequencing, the enzyme that removes unused dNTPs is _____________. A. luciferase B. ATP sulfurylase C. apyrase D. pyrophosphatase E. DNA polymerase
C. apyrase
In DNA replication, the function of SSBP is: A. enzymatically links Okazaki fragments. B. only needed on the lagging strand. C. to bind ssDNA & prevent annealing D. to unwind the DNA double helix. E. referred to as a molecular zipper.
C. to bind ssDNA & prevent annealing
The peptide sequence shown below is in an alpha-helix located on the periphery of a domain, with some of its side chains oriented towards the interior of the protein and others oriented towards the solvent. What is the most likely amino acid identity of position X? peptide = IQD X RHLT A) D B) N C) K D) M E) S
D) M
Which of the following statements is correct for hemoglobin and oxygen transport? A) O2 binds to the proximal histidine residue of the globin chain. B) Bonding of carbon dioxide to hemoglobin molecules increases O2 binding. C) 2,3-bisphosphoglycerate preferentially binds to oxyhemoglobin and stabilizes it. D) The binding of each O2 molecule to hemoglobin increases its affinity for the next O2 molecule. E) O2 binding causes hemoglobin to unfold.
D) The binding of each O2 molecule to hemoglobin increases its affinity for the next O2 molecule
A group of genes co-transcribed from a single promoter is referred to as: A) a transcription bubble. B) a Pribnow gene set. C) a fused gene. D) an operon. E) a functional gene unit.
D) an operon.
A frameshift mutation typically: A) changes only one codon. B) causes amino acids to attach to the wrong tRNAs. C) is a silent mutation. D) mutates the affected codon and all codons downstream. E) causes tRNA acceptor stems to be deficient.
D) mutates the affected codon and all codons downstream.
An exception(s) to the Central Dogma is: A) direct translation of DNA to proteins in some protozoans B) reverse translation in some protozoans C) RNA replication in some plants D) reverse transcription in some viruses E) transcription of bacterial DNA
D) reverse transcription in some viruses
How many molecules of acetyl-CoA and malonyl-CoA are used as Substrates during fatty acid synthesis by the synthase/acyl carrier protein (ACP) to make one palmitic acid molecule? A. 7 and 1 B. 0 and 8 C. 3 and 4 D. 1 and 7 E. 8 and 0
D. 1 and 7
Which of the following components are needed to obtain a product via PCR? 1- Taq or Pfu ANSWERS: A. 1, 2, 3, 4, 5, 6, 7 2- dNTPs (dATP, dCTP, dGTP, dTTP) B. 1, 2, 3, 5, 6, 7 3- template DNA C. 1, 2, 3, 5 4- endonucleases D. 1, 2, 3, 5, 7 5- primers E. 1, 2, 3, 4, 5, 7 6- ligase 7- cycles of heating and cooling
D. 1, 2, 3, 5, 7
Which statements about the genetic code are CORRECT? 1) The first two nucleotides of a codon are often enough to specify a given amino acid 2) The code is overlapping 3) One codon specifies only one amino acid 4) All 64 codons specify for an amino acid 5) Most amino acids have multiple codons ANSWERS: A. 1, 2, 3 B. 2, 3, 4 C. 3, 4, 5 D. 1, 3, 5 E. 2, 4, 5
D. 1, 3, 5
Which answer describes the NET number of high energy compounds generated from one acetyl group as it passes through the CITRIC ACID CYCLE? A. 1 NADH, 2 FADH2, 1 GTP/ATP B. 2 NADH, 2 FADH2, 2 GTP/ATP C. 2 NADH, 1 FADH2, 1 GTP/ATP D. 3 NADH, 1 FADH2, 1 GTP/ATP E. 3 NADH, 1 NADPH, 1 ATP
D. 3 NADH, 1 FADH2, 1 GTP/ATP
Which of the following statements are CORRECT concerning the electron transport chain (ETC)? #1: the ETC is a static set of protein complexes arranged in order from complex I-complex V #2: most of the complexes in the ETC are single protein complexes #3: the high degree of surface area of the cristae is key for ETC function #4: complex I-V actively pump protons across a membrane #5: the accumulation of protons in the intermembrane space provides energy for ATP synthesis #6: complex V is also known as ATP synthase A. 1, 3, 6 B. 2, 5, 6 C. 3, 4, 5, 6 D. 3, 5, 6 E. 2, 3, 5
D. 3, 5, 6
Which of the following is a requirement for RNA polymerase to function? A. The four nucleoside triphosphates: ATP, GTP, TTP, and CTP. B. Divalent cations, either Fe2+ or Ca2+. C. A free 3'-hydroxyl. D. A DNA template. E. An optimal Shine-Dalgarno sequence.
D. A DNA template.
Which molecule activates phosphofructokinase-1 kinase activity in mammals? This form of activation is particularly important during exercise, A. Glucose B. Citrate C. Pyruvate D. AMP E. ATP
D. AMP
Which statement describes a common feature shared between E. coli RNA polymerase and eukaryotic RNA polymerase II: A. Both are regulated by simple transcriptional elements. B. Both produce mature transcripts that are rarely processed. C. They are both regulated by equally complex cis and trans regulatory elements. D. Both prefer to bind an A/T rich sequence in the promoter region. E. The mediator complex is key to both of their functions.
D. Both prefer to bind an A/T rich sequence in the promoter region.
Which coenzyme participates in oxidation-reduction reactions? A. Thiamine pyrophosphate B. Tetrahydrofolate C. CoA D. FAD E. Pyridoxal 5' Phosphate
D. FAD
EF-Tu along with ________ positions the correct aa-tRNA into _______ of the ribosome. A. GDP; site P. B. GTP; site P. C. ATP; site P. D. GTP; site A. E. GDP; site A
D. GTP; site A.
High levels of ammonia in the bloodstream are toxic. Glutamine appears to be a general carrier of nitrogen between tissues. The assimilation of ammonia to generate glutamine is catalyzed by: A. Glutamate dehydrogenase B. Transaminase (aminotransferase) C. Alpha-keto acid dehydrogenase D. Glutamine synthetase E. Acyl-CoA synthetase
D. Glutamine synthetase
Where are glycoproteins with O-linked sugars made in cells, and what type of amino acid(s) are the sugars attached to? A. ER, serine and arginine B. Golgi apparatus, asparagine C. ER, asparagine D. Golgi apparatus, serine and threonine E. Plasma membrane, serine and threonine
D. Golgi apparatus, serine and threonine
Which answer describes a feature of a fatty acid with one or more double bonds? A. They have no bends in them and have a straight or cylindrical shape B. They do not rotate in the 2-dimensional plain of a membrane leaflet C. They flip rapidly from one leaflet of a membrane to the other leaflet D. Increasing their concentration lowers the melting temperature of a membrane E. They have no effect on the fluidity of a biological membrane
D. Increasing their concentration lowers the melting temperature of a membrane
Which of the following statements about recombination is TRUE? A. Homologous recombination occurs between pieces of DNA that have unrelated sequences. B. In E. coli, the process is initiated by MutH. C. RAD51 ligates the helices back together. D. It is an important mechanism to repair dsDNA breaks. E. In eukaryotes, the process is driven by Holliday proteins.
D. It is an important mechanism to repair dsDNA breaks.
The metabolic pathways and enzymes are not all localized in the same subcellular compartment in eukaryotes. Indicate the subcellular location for the Urea Cycle. A. Nucleus and cytosol B. Proteasome and Cytosol C. Mitochondrial matrix and lysosome D. Mitochondrial matrix and Cytosol E. Inner mitochondrial membrane and secretory vesicle
D. Mitochondrial matrix and Cytosol
Which answer describes a compound that MOST readily accepts electrons and has the MOST positive reduction potential? A. FAD B. Succinate C. Ubiquinone/Q D. O2 E. NAD+
D. O2
Glucagon in liver and epinephrine in muscle promote GLYCOGEN BREAKDOWN by activating ________________ (the first protein kinase in a G-protein kinase cascade), which then phosphorylates and activates ________________________. A. Protein kinase A, glycogen phosphorylase a B. Protein kinase C, phosphorylase kinase C. PDK1, glycogen phosphorylase b D. Protein kinase A, phosphorylase kinase E. Protein kinase C, glycogen phosphorylase b
D. Protein kinase A, phosphorylase kinase
Which of the following techniques separates a mixture of proteins on the basis of size? A. Ion-exchange chromatography B. Affinity chromatography C. Salting out D. SDS-PAGE E. Immunoblotting (Western blot)
D. SDS-PAGE
Which statement about translation is CORRECT. A. Peptide bond formation occurs at the E site. B. The ribosome typically moves one codon at a time in the 3' to 5' direction. C. Aminoacyl tRNAs enter the ribosome at the P site. D. The growing polypeptide exits through a channel near the P site. E. The ribosome binds 3 aminoacyl tRNAs at any given time.
D. The growing polypeptide exits through a channel near the P site.
Which answer is CORRECT regarding RNA polymerization? A. The promoter is typically downstream of the transcriptional start site. B. The +1 position is the location of the TATA box. C. The RNA pol alpha subunits contain the site where polymerization activity is located. D. The sigma factors assists in promoter selection. E. RNA pol moves from downstream to upstream in generating a transcript.
D. The sigma factors assists in promoter selection.
Which statement about plasmids is CORRECT? A. Plasmids are large pieces of DNA, typially >5 megabases. B. They typically contain a multiple cloning site within the antibiotic resistance gene. C. The antibiotic resistance is typically from a ROP gene. D. They replicate independent of the host DNA. E. Plasmid genes are not translated into proteins.
D. They replicate independent of the host DNA.
What is the sequence of the mRNA molecule synthesized from a DNA template strand having the following sequence? ATCGTACCGTTA. A. TAACGGTACGAT B. TAGCATGGCAAT C. UAGCAUGGCAAU D. UAACGGUACGAU E. AUCGUACCGUUA
D. UAACGGUACGAU
Shine-Delgarno sequences: A. are typically found in the 3' UTR of mRNA. B. are key promoters of transcription. C. are inhibitors of translation. D. direct the protein synthesis machinery to the start site of an mRNA. E. direct DNA replication.
D. direct the protein synthesis machinery to the start site of an mRNA.
In DNA repair, _________ breaks phosphodiester bonds, but __________ does not. A. DNA photolyase, AlkA glycosylase B. AlkA glycosylase, BRCA1 C. direct repair, UvrABC D. general excision repair, direct repair E. AP endonuclease, general excision repair
D. general excision repair, direct repair
To generate inosinate, __________ at the __________ position is deaminated at C-2 A. uracil; 3' anti-codon B. adenine; 3' anti-codon C. adenine; 5' anti-codon D. guanine; 5' anti-codon E. guanine; 3' anti-codon
D. guanine; 5' anti-codon
Which answer BEST describes the meaning of kcat in Michaelis-Menten kinetics? A. the equilibrium constant for the reaction. B. the maximum rate of the reaction. C. the substrate concentration that gives 1/2 maximum reaction rate. D. the rate of product formation. E. the rate of ES complex formation.
D. the rate of product formation.
Enzymes catalyze reactions by: Decreasing the free energy of activation Increasing the free energy of the system so that the change in free energy is positive Increasing the free energy of the substrate so that it is greater than the free energy of the product Changing the equilibrium constant for the reaction Decreasing the free energy of the enzyme-substrate complex
Decreasing the free energy of activation
Which statement concerning the Central Dogma is TRUE? A) There are no exceptions to the central dogma. B) Some protozoans directly translate proteins from DNA. C) Reverse translation occurs in most organisms and most human cells. D) Viral reverse transcriptase synthesizes protein from RNA. E) RNA to protein is irreversible.
E) RNA to protein is irreversible.
The fact that the genetic code is degenerate refers to which of the following? A) A codon is three nucleotides in length. B) The genetic code is non-overlapping. C) There are multiple reading frames within mRNA. D) tRNA molecules are the adapters between mRNA and proteins. E) There is more than one codon for most amino acids.
E) There is more than one codon for most amino acids.
Multiple transcription factors bind the RNA polymerase II promoter to initiate transcription. The TFIID complex: A) phosphorylates the N-terminal domain of polymerase. B) phosphorylates the C-terminal domain of polymerase. C) recruits RNA-processing enzymes. D) binds to the downstream promoter element (DPE). E) binds to the TATA-box.
E) binds to the TATA-box.
If tRNA nucleotidyl transferase fails to perform its function, what is the most likely consequence? A) tRNA Watson-Crick base pairing will be affected. B) Amino acids will attach to the wrong tRNAs. C) Eukaryotic mRNA will not receive the 5' cap. D) tRNA anticodon loops will be deficient. E) tRNA acceptor stems will be deficient.
E) tRNA acceptor stems will be deficient.
Acetylation of lysine residues on histone tails promotes: A) histone tails interacting with DNA. B) coactivators interacting with DNA. C) RNA polymerase II interacting with acetyllysine residues. D) ribosomes interacting with mature mRNA. E) transcription factors interacting with the acetyllysine residues.
E) transcription factors interacting with the acetyllysine residues.
What percentage of the human genome is considered to be "active" and needed? A) ~10% B) 10-25% C) ~33% D) 50-60% E) ~80%
E) ~80%
Which of the techniques listed below were used by Meselson and Stahl in the experiment that we discussed? 1. N14 and N15 2. Western blotting analyses 3. Ultracentrifugation 4. Sanger sequencing 5. Pulse-chase experiments A. 1, 2, 3, 4, 5 B. 1, 2, 3, 4 C. 1, 2, 3, 5 D. 1, 3, 4 E. 1, 3, 5
E. 1, 3, 5
Which enzymes from the list are components of the general excision-repair pathway in E. coli? Answers Enzyme 1: UvrABC A. 1, 2, 3 Enzyme 2: Rad51 B. 1, 3, 4, 5 Enzyme 3: DNA photolyase C. 4, 5, 6 Enzyme 4: DNA pol I D. 1, 2, 3, 6 Enzyme 5: BRACA2 E. 1, 4, 6 Enzyme 6: DNA ligase
E. 1, 4, 6
What is the correct order of events for eukaryotic DNA replication of the lagging strand? 1-DNA pol III generates the lagging strand from 5' to 3' 2-Helicase unwinds DNA and primosome generates a RNA primer 3-DNA ligase seals the adjacent DNA fragments 4-DNA pol I removes the RNA primer & synthesizes DNA replacement Answers A. 1, 2, 3, 4 B. 2, 1, 3, 4 C. 2, 4, 1, 3 D. 2, 4, 3, 1 E. 2, 1, 4, 3
E. 2, 1, 4, 3
Which phrase best describes the electron transport chain? A. A series of proton transfers from NADH to H20 B. A series of electron transfers from NAD+ to O2 C. A series of proton transfers from NADPH to O2 D. A series of proton transfers from NADH to O2 E. A series of electron transfers from NADH to O2
E. A series of electron transfers from NADH to O2
Which statement is TRUE about DNA replication? A. There are only two distinct stages: initiation and elongation. B. The process is carried out by a single multi-domain protein. C. Much of what we know about the process was first studied using human proteins. D. The process is slow to eliminate all errors. E. A template strand is required.
E. A template strand is required.
Which type of membrane transport requires energy and moves molecules against a concentration gradient? A. Simple diffusion B. Channels C. Facilitated diffusion D. Pores E. Active transport
E. Active transport
Which answer regarding a point mutation is the most complete? A. Changes only one codon. B. Causes a one amino mutation. C. Is a silent mutation. D. Results in a missense mutation. E. Can result in any of the above.
E. Can result in any of the above.
Which compound is both an intermediate in the citric acid cycle, an intermediate/precursor in fatty acid synthesis and an activator which stimulates polymerization of the first enzyme in the fatty acid synthesis pathway to increase its activity? A. Fumarate B. Oxaloacetate C. Malate D. Pyruvate E. Citrate
E. Citrate
A loss-of-function mutation in a cell's EF-Tu gene would DIRECTLY impact which process? A. Polypeptide exit through the channel in the A position. B. Initiation at the 5' cap of mRNA. C. Formation of the peptide bond. D. Charging of aminoacyl-tRNAs. E. Entrance of tRNAs into the ribosome.
E. Entrance of tRNAs into the ribosome.
The Ames test utilizes the Salmonella bacterium to test: A. For food poisoning. B. The activity of RNA pol III. C. For BRCA1 mutations. D. For homologous recombination. E. For mutagenic chemicals
E. For mutagenic chemicals
What two reactions must take place to generate a charged tRNA? A. Formation of phosphodiester bonds and splicing of DHU loop arm B. Formation of aminoacyl adenylate and phosphorylation of 5' terminus C. Formation of aminoacyl guanylate and splicing of DHU loop D. Formation of aminoacyl guanylate and aminoacyl-tRNA E. Formation of aminoacyl adenylate and aminoacyl-tRNA
E. Formation of aminoacyl adenylate and aminoacyl-tRNA
Which of the following is CORRECT concerning DNA polymerase III? A. It adds 3 nucleotides at a time. B. It is a distributive enzyme. C. The a-subunit of DNA pol surrounds DNA. D. It always synthesizes DNA in the 3' to 5' direction. E. It requires a free 3' hydroxyl to synthesize a polynucleotide chain.
E. It requires a free 3' hydroxyl to synthesize a polynucleotide chain.
The synthesis of carbamoyl phosphate is the first step in the Urea Cycle. This synthetic reaction occurs in the ______________. A. Nucleus B. Cytosol C. Proteasome D. Secretory vesicle E. Mitochondria
E. Mitochondria
Which statement comparing DNA replication to transcription is TRUE? A. Only DNA replication requires a multi-protein polymerase. B. Only DNA replication is highly processive. C. Both processes involve polymerization in the 3' to 5' direction. D. Both processes have a high degree of proof reading. E. Only DNA replication requires a primase to make primers.
E. Only DNA replication requires a primase to make primers.
Which statement about protein folding is TRUE? A. Non-polar residues cluster on the outside of the protein. B. Disulfide bonds are required for proteins to fold properly. C. The free energy of the unfolded proteins is at the global minimum. D. Protein folding occurs by a single defined pathway. E. Protein folding is an entropy-driven process.
E. Protein folding is an entropy-driven process.
A mutation in the Sigma factor gene would most likely result in which of the following? A. RNA pol prefers to bind introns. B. DNA pol is less processive. C. RNA pol is less processive. D. DNA pol binds non-specifically to DNA. E. RNA pol binds non-specifically to DNA.
E. RNA pol binds non-specifically to DNA.
If a stem cell has a mutation in a gene resulting in chromosome shortening, which of the following enzyme activities would you expect to be defective? A. DNA polymerase I B. MutS C. Phosphodiesterase D. MutL E. Telomerase
E. Telomerase
For the codon sequence 5' AUGCGA 3,' what is the 5' to 3' anticodon sequence? A. TACGCT B. AUGCGA C. AGCGUA D. UACGCU E. UCGCAU
E. UCGCAU
Which statement about mitochondria is TRUE? A. The mitochondrial inner membrane space contains enzymes for the citric acid cycle B. Complex IV is completely located inside the matrix C. Proteins that behave as uncouplers block proton translocation D. Electron transport is the key function of complexes located in the matrix E. Uncouplers allow O2 to be consumed without ADP
E. Uncouplers allow O2 to be consumed without ADP
The function of SSBP is to _________. A. remove the RNA primer B. connect the pieces of DNA in a processive manner C. proofread and correct errors D. mark the site of initiation E. bind single-stranded DNA to prevent annealing
E. bind single-stranded DNA to prevent annealing
The signal recognition particle (SRP) typically: A. consists of a 9-12 hydrophobic amino acid at the N-terminus of a protein. B. binds the N-terminal, hydrophilic peptide & directs the complex to the ER. C. binds the C-terminal, hydrophilic peptide & directs the complex to the Golgi. D. binds the N-terminal, hydrophilic peptide & directs the complex to the Golgi. E. binds the N-terminal, hydrophobic peptide & directs the complex to the ER.
E. binds the N-terminal, hydrophobic peptide & directs the complex to the ER.
The article "A lethal dose of RNA" discusses how Monsanto has developed a _________ that targets an essential gene in ___________. This plant pest causes a billion dollars' worth of damage in the US annually. A. mRNA; mice B. mRNA; fungus C. dsRNA; fungus D. dsRNA; grasshoppers E. dsRNA; a beetle larvae
E. dsRNA; a beetle larvae
Telomeres are: A. enzymes found in most cell types that lengthen the ends of chromosomes. B. the midpoint of linear chromosomal DNA. C. found in most bacterial chromosomes. D. uniquely susceptible to damage by endonucleases. E. often rich in guanine repeats.
E. often rich in guanine repeats.
Which answer explains why only copies of mRNAs are included in a cDNA library? A. Nothing, cDNA libraries typically include all types of RNA. B. restriction endonucleases C. reverse transcriptase D. RNAse H E. poly deoxy-thymine oligonucleotides
E. poly deoxy-thymine oligonucleotides
BEST SUBSTRATE
HIGHEST KCAT
The semi-conservative model of replication states that: a Both parental DNA strands stay together after replication. b The DNA double helix contains one parental and one daughter strand after replication. c Parental and daughter DNA are interspersed in both strands after replication. d DNA is conserved in the cytoplasm and nucleus. e DNA is a double helix with hydrogen bonded-bases in the center of the helix.
b The DNA double helix contains one parental and one daughter strand after replication.
RNA polymerase moves in the ___________ direction and the template strand is copied from ____________. a. 3' to 5' & 3' to 5' b. 5' to 3' & 5' to 3' c. 5' to 3' & 3' to 5' d. 3' to 5' & 5' to 3' e. The directions are different in prokaryotic and eukaryotic cells.
c. 5' to 3' & 3' to 5'
For many E. coli genes, which of the following DNA sequences would be the strongest promoter at the -10 position? a. GGCCC b. CGCTAA c. TATAAT d. TATGGT e. TTGACA
c. TATAAT
The E. coli Rho protein: A. enhances promoter clearance and shifts RNA Pol to the elongation stage. B. stalls promoter clearance and slows down transcription. C. increases the affinity of the core polymerase for specific promoter sequences. D. strengthens RNA-DNA hybrids in the middle of transcripts to enhance transcription. destabilizes the RNA-DNA hybrid and terminates transcription
e. destabilizes the RNA-DNA hybrid and terminates transcription
