mcq Flashcards
In a Lineweaver-Burk double-reciprocal plot of enzyme kinetics, what is indicated by the y-
intercept?
a) KM
b) -1/KM
c) -Vmax
d) 1/Vmax
d. 1/Vmax
What is indicated by the KM of an enzyme?
a) The substrate concentration at which 50% of the enzyme active sites are occupied by substrate
b) The substrate concentration at which all of the enzyme active sites are occupied by substrate
c) The substrate concentration at which the reaction rate is maximal
d) Half the initial rate of an enzyme reaction
a. The substrate concentration at which 50% of the enzyme active sites are occupied by substrate
What is the dependent variable for a standard curve in a Biuret assay for proteins?
a) Absorbance
b) Protein concentration
c) Biuret reagent
d) The x-axis
a. absorbance
What is a strong acid?
a) An acid that partially dissociates to a proton and its conjugate base
b) An acid that dissociates completely to a proton and its conjugate acid
c) An acid that dissociates completely to a proton and its conjugate base
d) An acid that dissociates completely to its component atoms
c. An acid that dissociates completely to a proton and its conjugate base
What are the roles of SDS in SDS-polyacrylamide gel electrophoresis?
a) It denatures the proteins and confers a negative charge on them
b) It allows the acrylamide to polymerise efficiently
c) It stains the proteins a blue colour, allowing their detection
d) It degrades nucleic acids and allows proteins to be separated efficiently
a) It denatures the proteins and confers a negative charge on them
A Lineweaver-Burk double-reciprocal plot is frequently used for estimating Vmax for an enzyme-
catalysed reaction because extrapolation of a line is easier than extrapolating a curve. An estimate of
Vmax is usually necessary because of technical difficulties in attaining high values of:
a) Substrate concentration
b) Enzyme concentration
c) Inhibitor concentration
d) Buffer concentration
a) Substrate concentration
Give the chemical formula of the conjugate base for CH3COOH.
a) CH3CONHCH3
b) CH3COCH3
c) CH3CONH3
d) CH3COO-
d) CH3COO-
Which of the following would not be suitable as the stationary phase in size exclusion
chromatography?
a) Dextran
b) Tris-Cl
c) Agarose
d) Polyacrylamide
b. Tris-Cl
Histidine’s affinity for Ni2+ is based on which property of the amino acid?
a) Its size
b) Its charge
c) Its hydrophobicity
d) Its carboxyl group
b. its charge
Which of these is not a commonly used biochemical buffer?
a) Tris
b) SDS
c) PIPES
d) HEPES
b. SDS
What gel electrophoresis matrix is most commonly used to separate DNA molecules in the 200bp
to 10kb size range?
a) Polyacrylamide
b) Agarose
c) Polysaccharide
d) Nylon
b. agarose
What is the role of SDS in SDS-polyacrylamide gel electrophoresis?
a) It allows the acrylamide to polymerise efficiently
b) It stains the proteins a blue colour, allowing their detection
c) It degrades nucleic acids and allows
d) It denatures and unfolds the proteins in the gel
d. It denatures and unfolds the proteins in the gel
Which of the following lists the minimum requirements for the polymerase chain reaction?
a) Template DNA, primers, thermostable DNA polymerase, deoxynucleotide triphosphates,
reverse transcriptase
b) Template DNA, primers, thermostable DNA polymerase, deoxynucleotide triphosphates
c) Template DNA, primers, thermostable RNA polymerase, deoxynucleotide triphosphates
d) Template DNA, RNase A, primers, thermostable DNA polymerase, deoxynucleotide
triphosphates
b. Template DNA, primers, thermostable DNA polymerase, deoxynucleotide triphosphates
What is the conjugate acid of sodium bicarbonate (NaHCO3)?
a) HCO3-
b) Na+
c) H2CO3
d) H
a) HCO3-
Give the chemical formula of the conjugate base for H3PO4.
a) H2PO4-
b) PO4-
c) H3PO4+
d) H3PO4-
a) H2PO4-
How many autosomes (non-sex chromosomes) are present in human diploid cells?
a) 46
b) 44
c) 2
d) 22
b. 44
What enzymes are used to convert large DNA molecules into fragments of defined length?
a) DNA polymerases
b) Restriction endonucleases
c) Reverse transcriptases
d) DNA ligases
b. restriction endonucleases
In what geographical location were bacteria discovered that contained a DNA polymerase that
facilitated efficient PCR?
a) The Grand Canyon (USA)
b) Yellowstone national park (USA)
c) Antarctica
d) Galway Bay (IRL)
b) Yellowstone national park (USA)
Variation in the intron of which gene is used to determine sex in DNA profiling?
a) Actin
b) beta-galactosidase
c) Amylase
d) Amelogenin
d. amelogenin
Which of the following are NOT repetitive elements in the human genome?
a) Poly A
b) Satellite DNA
c) Alu elements
d) LINEs
a. Poly A
Paul Ehrlich discovered Salvarsan, the first synthetic drug, and a successful treatment for
syphilis. He did this:
a) By theorizing that amongst the hundreds of newly synthesized organo-arsenic compound one
of them would be selective against T. pallidum
b) By theorizing that amongst the hundreds of newly synthesized organo-arsenic compound one
of them would be disrupt the T. pallidum cell wall
c) By theorizing that amongst the hundreds of newly synthesized organo-arsenic compound one
of them would prevent T. pallidum from entering its host
d) By serendipity
a) By theorizing that amongst the hundreds of newly synthesized organo-arsenic compound one
of them would be selective against T. pallidum
What is the Therapeutic Window for a drug?
a) The range of drug doses that remain safe
b) The maximum safe dose divided by the minimum safe dose
c) The minimum safe dose divided by the maximum safe dose
d) The range of drug doses that can effectively treat disease while remaining safe
d) The range of drug doses that can effectively treat disease while remaining safe
World-wide, gene therapy trials are:
a) Decreasing due to the Jesse Gelsinger tragedy
b) Increasing due to the potential of this therapeutic treatment
c) Being abandoned for safety reasons
d) Saving millions of patients
b) Increasing due to the potential of this therapeutic treatment
What are drugs?
a) Substances that, when absorbed, alter normal bodily functions
b) Substances found in nature
c) Substances used to treat disease
d) Substances that, when absorbed, stimulate biochemical pathways
a) Substances that, when absorbed, alter normal bodily functions
Oncogenic activation of proto-oncogenes results from:
a) Inappropriate activation of normal growth promoting genes
b) The induction of cancer
c) Down regulation of genes that prevent cancer
d) Excessive out of control cell proliferation
a) Inappropriate activation of normal growth promoting genes
How is chain termination in Sanger DNA sequencing achieved?
a) Deoxynucleotides
b) Dideoxynucleotides
c) Amino acids
d) Ribonucleotides
b) Dideoxynucleotides
Pulsed field gel electrophoreisis (PFGE) was specifically developed to separate what class
of molecules?
a) RNA
b) short DNA fragments
c) long DNA fragments
d) histones
c) long DNA fragments
Inter-individual variation in what class of DNA elements is exploited in DNA profiling?
a) promoters
b) expressed sequence tags (ESTs)
c) exons
d) short tandems repeats (STRs)
d) short tandems repeats (STRs)
What is the average length of oligonucleotide primers used in PCR?
a) 6 nucleotides
b) 10 nucleotides
c) 20 nucleotides
d) 50 nucleotides
c) 20 nucleotides
Which of the following cloning vector types was the workhorse of the human genome
project due its large insert size?
a) BACs
b) Plasmids
c) Phage Lambda
d) Retroviral
a. BACs
What is the dependent variable in a standard curve for inorganic phosphate (Pi)?
a) Absorbance
b) Pi concentration
c) Acid molybdate reagent
d) The x-axis
a. absorbance
For enzymes with Michaelis-Menten kinetics, what is represented by KM?
a) ½ [S] when V0 = ½ Vmax
b) [S] when V0 =Vmax
c) [S] when V0 = 2*Vmax
d) [S] when V0 = ½ Vmax
d) [S] when V0 = ½ Vmax
Which term below best describes Molecular Medicine:
a) The use of drugs in medicine
b) Basic research that underpins medicine
c) Scientific methodology applied to the cellular and molecular basis of health
d) Medicinal chemistry
c) Scientific methodology applied to the cellular and molecular basis of health
Loss of tumour suppressor function is caused by:
a) Recessive mutation of cancer genes
b) Epigenetic up-regulation of cancer gene
c) Lost or reduced expression of genes that restrain growth
d) Accelerated cell proliferation
c) Lost or reduced expression of genes that restrain growth
A recombinant DNA molecule is defined as…..
a) a DNA molecule containing covalently linked segments derived from two or more DNA sources
b) reverse transcribed mRNA
c) a DNA molecule that contains sites recognized by restriction enzymes
d) a DNA molecule that confers antibiotic resistance to bacteria
a) a DNA molecule containing covalently linked segments derived from two or more DNA sources
Which of the following is NOT a plasmid vector?
a) phage λ
b) pUC18
c) pBR322
d) pET-15B
a) phage λ
What enzyme is used to produce cDNA from mRNA?
a) DNA polymerase
b) Ligase
c) Reverse transcriptase
d) Restriction enzyme
c) Reverse transcriptase
At what temperature is the denaturation step in each cycle of a PCR reaction usually performed?
a) 60 C
b) 50 C
c) 95 C
d) 72 C
c) 95 C
What dye included in a qPCR reaction allows quantitation of target DNA in a test sample?
a) Commassie blue
b) Ethidium bromide
c) Sybr Green
d) xGa
c) Sybr Green
Differences in intron 1 of the amelogenin (AMEL) gene can be used……
a. to determine the sex of human DNA samples
b. to study variable numbers of tandem repeats in the human genome
c. to identify STRs on human chromosome 22
d. in RFLP analysis
a. to determine the sex of human DNA samples
What technique is used to identify Short Tandem Repeat (STR) length variants in DNA profiling?
a. Protein expression
b. DNA sequencing
c. Multiplex PCR
d. Southern blotting
c. Multiplex PCR
Which of the following is an affinity tag that permits purification of recombinant proteins on nickel agarose?
a. 6 His
b. IPTG
c. Lac
d. GFP
a. 6 His
What is a sequence contig?
a. A class of gene
b. An assembly of overlapping DNA sequences
c. An assembly of non overlapping DNA sequences
d. Repetitive DNA
b. An assembly of overlapping DNA sequences
In relation to the Human Genome project what was the purpose of Sequence-Tagged Sites (STSs)?
a. Cytogenetics
b. Gene identification
c. Generation of a high resolution physical map
d. Gene expression
c. Generation of a high resolution physical map
What is the approximate size of the Human Genome?
a. 3000 Mb
b. 30 basepairs (bp)
c. 3000 kilobases (kb)
d. 30 megabases (Mb)
a. 3000 Mb
What is the typical length of high quality sequence obtained from a single sequence run using the Sanger method?
a. 5-10 Megabases (Mb)
b. 5-100 bp
c. 5-10 kilobases (kb)
d. 500-1000 base pairs (bp)
d. 500-1000 base pairs (bp)
What modified nucleotide triphosphate causes chain termination in Sanger sequencing?
a. Di-
b. Deoxy-
c. Ribo-
d. Dideoxy-
d. Dideoxy-
What technique is used to separate large fragments of genomic DNA?
a. Ligation
b. Pulsed Field Gel Electrophoresis (PFGE)
c. Polymerase Chain Reation (PCR)
d. PolyAcrylamide Gel Electrophoresis (PAGE)
b. Pulsed Field Gel Electrophoresis (PFGE)
What is the typical insert size of a BAC clone?
a. 1-2 kilobases (kb)
b. 150-250 kb
c. 1-2 megabases (Mb)
d. 100-1000 basepairs (bp)
b. 150-250 kb
From the perspective of medicine, what is cancer:
a. A disease caused by the wrong cells in the wrong place
b. Hyper-proliferation of abnormal cells
c. Hyper-proliferation of normal cells
d. A illness caused by the presence of a tumour
d. A illness caused by the presence of a tumour
Ataxia telangiectasia (AT) is an inherited syndrome caused by mutation of ATM. The cardinal clinical phenotype of AT is:
a. Small size
b. Loss of neurons required for vision
c. Frequent colds
d. Loss of neurons required for coordinated growth
d. Loss of neurons required for coordinated growth
Carcinoma are tumours of ‘X’ origin. What is X:
a. Neuronal cell
b. Fibroblast cell
c. Haematopoietic cell
d. Epithelial cell
d. Epithelial cell
A checkpoint response is:
a. A permanent delay to cell cycle progression
b. A transient delay to cell cycle progression
c. Recovery of cell proliferation after DNA damage
d. Required for genome instability
b. A transient delay to cell cycle progression
The ATR kinase is recruited to single-stranded DNA via interaction with:
a. Replication Protein A (RPA) complex
b. MRE11-RAD50-NBS1 (MRN) complex
c. The RAD9-RAD1-HUS1 (9-1-1) complex
d. The β-catenin transcription factor
a. Replication Protein A (RPA) complex
The DNA Damage Response (DDR) is:
a. A biochemical signalling pathway that responds to Wnt signalling
b. A biochemical signalling pathway that responds to photons
c. A biochemical signalling pathway that coordinates the biological responses to DNA damage
d. A biochemical signalling pathway that kills cancer cells
c. A biochemical signalling pathway that coordinates the biological responses to DNA damage
What is gene therapy:
a. The transduction of DNA into the cells to kill them
b. The inhibition of gene expression
c. The transduction of DNA into the cells of a patient to alleviate disease
d. The development of drugs to inhibition gene function
c. The transduction of DNA into the cells of a patient to alleviate disease
Why is it important that the ideal gene therapy vector should be capable of transducing non-dividing cells:
a. Non-dividing cells are not involved in disease
b. Transduction of terminally differentiated cells does not cause an immunological response
c. Most tissues are composed of proliferating cells
d. Most tissues are composed of cells that are terminally differentiated
d. Most tissues are composed of cells that are terminally differentiated
Xenotropic cell targeting in gene targeting refers to:
a. The gene therapy vector is specific to a different host species
b.The gene therapy vector has a narrow host range
c. The gene therapy vector cannot infect any related species
d. The gene therapy vector has a wide host range
a. The gene therapy vector is specific to a different host species
Adeno-associate viral vectors (AAV) are particularly useful for gene therapy because:
a. Production is easy to scale-up
b. They have narrow trophism
c. They are non-pathogenic “dependoviruses”
d. They can be produced in non-specialist
c. They are non-pathogenic “dependoviruses”
In gene therapy, the humoural response of the host results in:
a. Death of the host
b. Production of antibodies against adenoviral proteins
c. Loss of immune memory cells
d. Resistance to the initial transduction
b. Production of antibodies against adenoviral proteins
Pharmcokinetics can be summarised as:
a. The study of study of natural products
b. The study of what the body does to the drug
c. The study of ‘drugable’ targets
d. The study of what the drug does to the body
b. The study of what the body does to the drug
Covalent bonds are not normally involved in ligand/receptor binding. What bonds are and what is their relative binding strength
a. van der Waal forces, ionic bonds and hydrogen bonds
b. van der Waal forces, hydrogen bonds and ionic bonds
c. Ionic bonds, hydrogen bonds and van der Waal forces
d. Hydrogen bonds, ionic bonds and van der Waal forces
c. Ionic bonds, hydrogen bonds and van der Waal forces
Binding affinity is a measure of how well a drug fits its receptor and is the sum total of all the intermolecular interactions. The dissociation constant (Kd) measures the tendency of the larger object (complex) to separate into its components. A good drug receptor fit will be
a. High affinity and low Kd
b. High affinity and high Kd
c. High affinity and high Kd
d. Low affinity and low Kd
a. High affinity and low Kd
During carcinogenesis neutral mutations are frequent. Which statement below best describes such mutations:
a. Mutations required for the continuous evolution of the cancerous phenotype
b. Mutations that have little of no affect on the aetiology of cancer
c. Mutations that subtly affect the phenotype of tumours
d. Mutations that occur in large, advanced tumours
b. Mutations that have little of no affect on the aetiology of cancer
Lawrence Loeb and colleagues proposed the somatic mutation hypothesis in 1974 which postulates that:
a. Normal cells have incredibly low mutation rates
b. Cancer cells lose tumour suppressors via epigenetic mechanisms
c. Cancer cells have significantly elevated mutation rates
d. Normal cells become cancerous by accumulating mutations
c. Cancer cells have significantly elevated mutation rates
