Molec cell lab final
Western blotting is the technique for the detection of... - A specific protein in a sample - A specific RNA in a sample - A specific DNA in a sample - A specific glycolipid in a sample
A specific protein in a sample
In your opinion as a young scientist in training, what would be an appropriate negative control for this experiment? - Distilled water - An infected sample - An uninfected sample - A sample from a person with no symptoms
An uninfected sample
The detection method used in our experiment to verify isolation of proteins on the western blot is called... - Colorimetric detection - Spectrum analysis - Chemiluminescent - UV analysis
Colorimetric detection
Plasmids are: a) Small, self-replicating, extrachromosomal, circular, double stranded DNA b) Often carry genes for antibiotic resistance c) Can not be transferred from one bacterium to another d) All of the above e) A & B only
A & B only
The best equipment to measure 175 µl (microliters) - A P-200 micropipette - A P-1000 micropipette - A graduated cylinder - A serological pipette
A P-200 micropipette
What enzyme is used to reverse transcribe RNA to DNA? - RNA dependent RNA polymerase - Reverse Transcriptase - DNA polymerase - RNA polymerase
Reverse Transcriptase
In ELISA, the enzyme, horseradish peroxidase (HRP) is bound to the - the tested sample - SARS-CoV-2 antigen - region of the secondary antibody - well of microtiter plate
SARS-CoV-2 antigen
What type of ELISA did we use to test for COVID-19? - Sandwich ELISA - Competitive ELISA - Direct ELISA - Indirect ELISA
Sandwich ELISA
_____________________binds to the first antibody and has the enzyme Alkaline Phosphatase - Secondary Antibody - Blocking solution (i.e. Milk) - BCIP/NBT - Primary antibody
Secondary Antibody
The rapid test is a - Qualitative screening test - Quantitative screening test - Molecular test - Serological test
Serological test Qualitative screening test
What is diffusion? - The net movement of anything from a region of lower concentration to a region of higher concentration. - The spontaneous net movement of solvent molecules through a selectively permeable membrane - A protein that serves the function of moving other materials within an organism. - The net movement of anything from a region of higher concentration to a region of lower concentration.
The net movement of anything from a region of higher concentration to a region of lower concentration.
Explain how reverse transcription works. - The polymerase enzyme converts RNA into cDNA - The reverse transcriptase enzyme amplifies DNA - The reverse transcriptase enzyme converts RNA into cDNA - The polymerase amplifies DNA
The reverse transcriptase enzyme converts RNA into cDNA
What is Km? a) The amount of substrate consumed per unit time. b) The substrate concentration at which v = ½ Vmax. c) The concentration of substrate at which v = [S]. d) ½ Vmax
The substrate concentration at which v = ½ Vmax.
Why must we practice social distancing during the outbreak of COVID-2019? - To help reduce socializing with people - To help the virus spread - None of these - To help prevent the spread of SARS-CoV-2 virus
To help prevent the spread of SARS-CoV-2 virus
Why is it necessary to wash the samples repeatedly in ELISA? - To remove any proteins or antibodies which are unbound - To enhance the interaction between antibody and antigen - To make the sample clean - To increase samples' concentration
To remove any proteins or antibodies which are unbound
What is the purpose of dialysis in the protein isolation? - To add salts to the samples - To remove salts from the samples - To balance out the samples - To keep the samples cold
To remove salts from the samples
PCR is a DNA amplification process. - True - False
True
In the ion exchange column ______________________ (weakest/strongest) ionic interactions will elute first, while ____________________ (weakest/strongest) ionic interactions will elute last. - Weakest, Strongest - Strongest, Strongest - Strongest, Weakest - Weakest, Weakest
Weakest, Strongest
Restriction enzymes are________ a) on the cellular membrane and restrict the trafficking of macromolecules into the cell. b) are specific proteases that clear specific and unique DNA sequences c) are specific ribonucleases, which can degrade mRNA after its synthesis. d) catalyze the addition of a phosphate group to certain proteins to activate them.
are specific proteases that clear specific and unique DNA sequences
You have isolated the enzyme Milleniase from the rare Y2K bug. This enzyme cleaves the first two numbers off of four digit dates. You flex your skills as an enzymologist and come up with the following graph of initial velocity as a function of substrate concentration: ( min:5, Max:35) What is the approximate value of Vmax? a) 17 b) 35 c) 5 d) 7
b) 35
If the recognition sequence of the restriction enzyme HindIII is AAGCTT, then how many covalent bonds will be broken by the enzyme in the following double strand DNA molecule? AAGCTTGAAGCTT a) 3 b) 4 c) 2 d) 1
b) 4
Pyruvate reacts with ____, which absorbs visible light at ___ nm: a) Malonate .. 450 b) DNPH .. 510 c) ATP .. 480 d) PEP .. 510
b) DNPH .. 510
DNA moves from the _______________ end to the ____________________ end in the gel electrophoresis because DNA is ____________________charged. a) Positive, negative, negatively b) Negative, positive, negatively c) Negative, positive, positively d) Positive, negative, positively
b) Negative, positive, negatively
What are some applications of restriction enzymes? a) They can be used for DNA fingerprinting. b) They can be used to assist insertion of genes into plasmid vectors during gene cloning. c) They can be used in mass protein production experiments. d) All of the above e) A & B only f) B & C only
f) B & C only
Following the genome alignment of the protein sequence, an * (asterisk) indicates amino acids that are dissimilar, and an empty space indicates that the amino acid position has the same amino acid in the alignment. True False
false
Restriction enzymes recognize specific sequences called genes. True False
false
The NCBI website provided us with the reference genome and in some cases the genetic map. True False
false
The closest genetic relative of SARS-CoV-2 is SARS-CoV-1. True False
false
The order of salt buffers added to the ion-exchange columns is high, medium, low concentration of salt. True False
false
The primers and probe are fluorescently labeled in qRT-PCR technique. True False
false
The serum samples' neutralization titer is expressed as reciprocal of lowest dilution. True False
false
What micropipette will you use to measure out 140 ul? - L-1000 - L-2 - L-200 - L-20
L-200
Interpret the results (only one line present at IgG) a) Negative b) IgG positive c) IgG and IgM positive d) Invalid e) IgM positive
invalid
Restriction enzymes bind to and cut sequences in DNA that are mostly: a) palindromic and random sequences b) palindromic c) none of the above d) random sequences
palindromic
In the gel electrophoresis the smaller fragments migrate at a faster rate compared to the larger fragments. True False
true
KM is a measure of the affinity of a substrate for the enzyme True False
true
Like all proteins, RuBisCo absorbs at 280nm. True False
true
Restriction enzymes are named according to the bacteria that produce them. True False
true
The 4 dNTPs (deoxynucleotide triphosphates) which are the building blocks of PCR include dATP, dGTP, dCTP, and dTTP. - True - False
true
The function of IgM's is to neutralize the SARS-CoV-2 virus by binding to its spikes and inhibiting infection of a body cell. True False
true
We need to determine the pH of a solution because an incorrect pH can affect the activity and structure of biomolecules such as proteins, sugars and nucleic acids - True - False
true
You should NEVER rotate the volume adjuster on a micropipette beyond the upper and lower limit. - True - False
true
How much of 12.5 M HCl have to be added to prepare 2 L of 5 M HCl? - 1.9 L - 0.8 L - 7.56 L - 21.0 L
0.8 L
Can asymptomatic individuals still transmit the virus? - Yes - Can't say - Maybe - No
Yes
FASTA provided the protein sequence for the spike protein of each virus. True False
true
What is the incubation period for COVID-19? - 5-15 days - 10 days - 2-14 days - 5 days
2-14 days
An antibody is... - Recognize antigens - Y shaped - Are also called immunoglobulins or Igs - Composed of glycoproteins - Made up of variable domains and a constant domain - All of the above
- All of the above
The step that is needed to make the Microneutralization assay quantitative is... - Prepare complete growth medium for cells by adding fetal bovine serum to a final concentration of 10%. - Two-fold serial dilutions of the serum - Add Crystal violet solution to stain the cells - Use the virus to infect the cultured cells in the plastic dishes
- Two-fold serial dilutions of the serum
How many types of controls do you need to have in the Microneutralization Assay? - No controls are need - Two; Sample Control and Virus Control - One; Virus Control - Two; Virus Control and Cell Control
- Two; Virus Control and Cell Control
Select the exception when describing HRP. - Used in microneutralization - An enzyme - Used in ELISA - Horseradish peroxidase
- Used in microneutralization
Seventy-five milliliters is equivalent to how many liters (L)? - 0.075 - 0.75 - 7.5 - 0.0075
0.075
The reliable absorption range of a spectrophotometer is ______. - 0.1-1.0 - 0.01-1.0 - 0.5-1.0 - 0-1.0
0.1-1.0
What is the molarity of 5g of NaOH in 750 mL of solution? MW of NaOH is 39.99 g/mol. - 167 M - 0.167 M - None - 0.0167 M
0.167 M
We need to prepare 50 mL of a solution, containing 5 grams/liter of salt. How many grams of salt do we need? - 5 g - 25 g - 10 g - 0.25 g
0.25 g
One milliliter equals to how much μL? - 100 - 1000 - 0.1 - 10
1000
Determine the amount of ammonium sulfate needed to reach 37% saturation level if you have 55mL. - 11550 grams - 11.55 grams - 1155 grams - 4.675 grams
11.55 grams
Make a 500 mL solution using 30 g/L KCl. - 100 g KCl - Not enough information to determine the amount - 20 g KCl - 15 g KCl
15 g KCl
Buffers are always used in what concentration - 10X - 2X - 5X - 1X
1X
Determine the amount of ammonium sulfate needed to reach 50% saturation level if you have 32mL. - 6.72 grams - 272 grams - 2.72 grams - 27.2 grams
2.72 grams
What wavelength does DNA absorb the most light at? - 400 nm - 260 nm - 200 nm - 280 nm
260 nm
The expression of the added gene(s) in GMOs is(are) often under the control of a ________________, which is _________________ in non-GMO organisms - 35S Promoter - 25S Promoter - present - not present
35S Promoter , not present
What defines the UV spectrum of light? - 200-400 nm - < 400 nm - > 400 nm - None of the above
< 400 nm
If a linear piece of DNA has four sites for a particular restriction enzyme, into how many fragments will that restriction enzyme cut the DNA? a) 2 b) 3 c) 4 d) 5
5
Calculate the grams of agarose needed to make a 50 mL 0.8% agarose gel in 1X TBE. Given: 10x TBE - 5 mL 10XTBE 0.4 g agarose - 50 mL 10XTBE 0.4 g agarose - 50 mL 10XTBE 4 g agarose - 5 mL 10XTBE 4 g agarose
5 mL 10XTBE 0.4 g agarose
In a lab session, you need to transfer 3.5 ml of NaOH from a 50 ml flask to a 25 ml beaker. Which of the following would be the best to use? - 25ml beaker - 5ml serological pipette - 50ml graduated cylinder - P10 micropipette
5ml serological pipette
Match each component to its function. A) __3__ Used for visual tracking of DNA migration during electrophoresis B) __4__ a DNA molecular weights standard used to compare unknown sizes of DNA fragments C) __1__ Buffer used for gel electrophoresis D) __2__ intercalating agent that binds to the ds DNA and enables its visualization under UV light 1. 1X TBE 2. Gel Star 3. Loading dye 4. Molecular ladder
A) 3 loading dye B)4 molecular ladder C) 1 1x tbe D) 2 gel star
In order to correctly load a micropipette with fluid you must ______________? - Add a tip and push the plunger to the first stop. - Turn the white wheel on the pump upward - Add a tip and push the plunger to the second stop - Push the eject button
Add a tip and push the plunger to the first stop.
When weighing solid chemicals, when should you tare the electronic scale? - Immediately upon turning on the scale - Prior to adding anything to the scale - After selecting and placing a weigh boat on the scale - After all material has been added to the scale for weighing
After selecting and placing a weigh boat on the scale
How can we reduce contamination in this experiment? - Clean pipettes/surface with 70% ethanol - Change pipette tips between samples and tubes - Use clean reagents - All of these
All of these
What does 'real time' mean in rRT-PCR? - A relatively small amount of PCR product can be quantified - It can be used to screen for results in Real-Time - We can monitor the progress of a PCR while its running - All of these choices
All of these choices
In our PCR experiment using GMOs, we amplified the 35S promoter and the tubulin gene. Why did we want to amplify the tubulin gene? a) Because we wanted to waste time and money b) Because the tubulin gene is an experimental control of DNA extraction c) Because the tubulin gene is an experimental control of the PCR reaction d) Because the tubulin gene provides instructions for making a structural protein called alpha-tubulin
B) Because the tubulin gene is an experimental control of DNA extraction
What are the steps of a western blot in order? - Blocking, addition of substrate, a combination of primary and secondary antibodies - Blocking, primary antibody, secondary antibody, addition of substrate - Primary antibody, blocking, secondary antibody, addition of substrate - Primary antibody, secondary antibody, blocking, addition of substrate
Blocking, primary antibody, secondary antibody, addition of substrate
Apart from detecting the existence of virus RNA, what other molecules can be detected to screen for SARS-CoV-2 virus? - Both Antibodies against the virus and Viral antigens - None of these - Viral antigens - Antibodies against the virus
Both Antibodies against the virus and Viral antigens
How is SARS-CoV-2 virus transmitted? - If someone infected sneezes or coughs on you - Both Coming in contact with infected droplets and If someone infected sneezes or coughs on you - Food - Coming in contact with infected Droplets
Both Coming in contact with infected droplets and If someone infected sneezes or coughs on you
Other known coronaviruses that have caused similar outbreaks. - SARS - Both SARS and MERS - MERS - Alphacoronavirus
Both SARS and MERS
How is cDNA produced? - By translation of viral proteins - By transcription of cell DNA - By reverse transcription of cellular RNA using reverse transcriptase enzyme - By reverse transcription of viral RNA using reverse transcriptase enzyme
By reverse transcription of viral RNA using reverse transcriptase enzyme
The number of cycles required for the fluorescent signal to cross the threshold of detection is defined as the __________________ ___________________ value. - Cycle threshold value (Ct) - Delta Ct value - Fluorescent value (Ft) - R2 Value
Cycle threshold value (Ct)
What enzyme is used to amplify the cDNA? - RNA polymerase - DNA polymerase - RNA dependent RNA polymerase - Reverse Transcriptase
DNA polymerase
Many enzymes function by __________ the activation energy of reactions a) None of these b) Neutralizing c) Decreasing d) Increasing
Decreasing
What step/s does rRT-PCR have in common with regular PCR? - Denaturation, Annealing, Elongation - Reverse transcription, Annealing - Annealing - Denaturation, Reverse transcription
Denaturation, Annealing, Elongation
What is the purpose of adding BCIP/NBT? - Confirm the presence of nucleic acids - Is produced as an immmune response - Is an enzyme for alkaline phosphatase - Enables us to visualize RuBisCo
Enables us to visualize RuBisCo
Select the correct order of the basic steps of ion-exchange chromatography. - Regeneration, elution, sample application, equilibrium - Elution, regeneration, equilibrium, sample application - Equilibrium, sample application, elution, regeneration - Equilibrium, sample application, regeneration, elution
Equilibrium, sample application, elution, regeneration
If only IgG antibodies are found in the blood of a patient, this informs us that the patient is experiencing an infection for the first time/recent infection of COVID-19. True False
False
The absorbance of a sample as measured by UV-visible spectrometry is inversely proportional to the concentration of the sample, such that, as the concentration increases, the absorbance decreases. True or false? - True - False
False
The purpose of Reverse Transcription primer is to amplify the RNA. True False
False
A_______ shows relative locations of genes and other important features in a genome. a) Phylogenetic tree b) Genetic map c) Plasmid map d) Protein sequence
Genetic map
The cells resulting from the microneutralization assay should be counted with a - Count the cells manually under a light microscope - Crystal violet stain - Hemocytometer - Spectrophotometer
Hemocytometer
The detection method of the rapid test uses the principle of a) Immunology b) Immunochromatography c) Immunosuppressants d) Immunoglobulins
Immunochromatography
What is the program setting for rRT-PCR? - In Stage 1, 2 min at 25°C; 1 Rep, In Stage 2, 15 min at 50°C; 1 Rep, In Stage 3, 2 min at 95°C, 1 Rep, In Stage 4, Step 1 set to 3 sec at 95°C, In Stage 4, Step 2 set to 30 sec at 55.0°C, In Stage 4, Reps should be set to 45 - In Stage 1, 15 min at 50°C; 1 Rep, In Stage 2, 2 min at 95°C, 1 Rep, In Stage 3, Step 1 set to 3 sec at 95°C, In Stage 3, Step 2 set to 30 sec at 55.0°C, In Stage 3, Reps should be set to 45 - In Stage 1, 2 min at 25°C; 1 Rep, In Stage 2, 15 min at 50°C; 1 Rep - In Stage 1, Step 1 set to 3 sec at 95°C, In Stage 2, Step 2 set to 30 sec at 55.0°C, In Stage 3, Reps should be set to 45
In Stage 1, 2 min at 25°C; 1 Rep, In Stage 2, 15 min at 50°C; 1 Rep, In Stage 3, 2 min at 95°C, 1 Rep, In Stage 4, Step 1 set to 3 sec at 95°C, In Stage 4, Step 2 set to 30 sec at 55.0°C, In Stage 4, Reps should be set to 45
What is occurring in row A? a: green antibodies--> dark purple b: blue antibodies ---> light purple - In the presence of antibodies, nothing occurs. - In the presence of nonspecific antibodies, - the virus can bind and kill cells. - In the presence of antibodies, the virions cannot infect cells. - In the presence of nonspecific antibodies, nothing occurs.
In the presence of antibodies, the virions cannot infect cells.
It suggests that binding of substrate changes shape of enzyme's active site or of the substrate in order to speed up a reaction in a) Enzyme affinity model b) Michaelis-Menten kinetics c) Induced fit model d) Lock and key model
Induced fit model
Positive controls are used to intentionally produce the expected result. Internal controls ensure that the experimental procedures are working as expected. Tubulin is used as a(n) _____________ control. - External - Positive - Negative - Internal
Internal
How does the fluorescent probe work during rRT-PCR? - It binds to a specific sequence on the viral cDNA target region - It is reverse transcribed - It is amplified by the primers - It binds to the viral RNA
It binds to a specific sequence on the viral cDNA target region
Coronavirus is a zoonotic disease: what does this mean? - None of these - It can only be transmitted between animals - It can be transmitted between animals and humans - It can only be transmitted between humans
It can be transmitted between animals and humans
The pH of a liquid solution is a measure of: - Molar concentration of Hydrogen ion - Electrical conductivity - Dissolved salt content - Hydroxyl ion molarity
Molar concentration of Hydrogen ion
The effect of inhibitors/activators on pyruvate kinase is an example of allosteric regulation. This effect can be explained mechanistically as follows: a) Molecules can bind to other sites remote from the active site, causing a conformational change and effecting activity b) This observation cannot be explained c) Irreversible binding to the active site d) It's just a matter of chance
Molecules can bind to other sites remote from the active site, causing a conformational change and effecting activity
What is the unit of absorbance which can be derived from Beer Lambert's law? - No unit - cm - l*mol-1 cm-1 - l*gm-1 cm-1
No unit
The formula to calculate the concentration of a DNA samples is: - OD280nm X 50 mg/ml - OD260nm X 50 mg/ml - OD260nm X 40 mg/ml - OD260nm X 40 mg/ml
OD260nm X 50 mg/ml
What is the purity ratio of DNA? - OD280nm/ OD260nm <1.8 - OD260nm/ OD280nm <1.8 - OD260nm/ OD280nm >1.8 - OD280nm/ OD260nm >1.8
OD260nm/ OD280nm >1.8
Pyruvate kinase catalyzes the following reaction: a) PEP + ATP → Pyruvate + ADP b) None of these c) PEP + MgCl2+ → Pyruvate + ATP d) PEP + ADP → Pyruvate + ATP
PEP + ADP → Pyruvate + ATP
In order to determine the size of the bands on the western blot, what must we do first? - Determine its OD using the spectrophotometer - Physically measure the distance from the well to the bands with a ruler to create a standard curve - Simply measure the distance from the well to the band in mm - Calculate its extinction coefficient
Physically measure the distance from the well to the bands with a ruler to create a standard curve
What is the purpose of using nonfat dry milk in protein isolation? - None of the above - Single population of antibodies that recognize a single specific epitope - A heterogenous population of antibodies that can recognize multiple epitopes on the same single protein - Prevents non-specific binding of antibody to the membrane, reduces background signal
Prevents non-specific binding of antibody to the membrane, reduces background signal
_____________________is a structure that is specific to RuBisCo and binds with the epitope if present - Secondary Antibody - BCIP/NBT - Primary antibody - Blocking solution (i.e. Milk)
Primary antibody
To measure the reaction product of an ELISA a specialized ________________ will read the microplate. - Centrifuge - Thermocycler - pH balance - Water bath - Spectrophotometer
Spectrophotometer
Which are the structural proteins of coronaviruses? - Spike, envelope, membrane, and nucleocapsid - P24, pre-capsid, VP1, VP2 - Capsid, neuraminidase, hemagglutinin, Sigma3, Mu1 - VP3, VP4, VP6, VP7
Spike, envelope, membrane, and nucleocapsid
What is correct about plasmids? a) They are extrachromosomal b) Serves as the only genetic material for most of the organisms c) They are single stranded d) They are fungi, that can cause diseases in humans
They are extrachromosomal
Order the steps of ELISA: ______ Addition of the substrate TMB into the microwells. ____ Microplate coated with an anti-IgM specific antibody. ____ Read the absorbance at 450 nm with a microplate reader. ____ Addition of controls and samples into the designated microwells. ____ Addition of stop solution. ____ TMB turns blue in IgM positive samples. ____ TMB turns yellow in IgM positive samples, due to the acidity of the stop solution. ____ Addition of HRP-labeled SARS-CoV-2 antigen.
__1__ Microplate coated with an anti-IgM specific antibody. __2__ Addition of controls and samples into the designated microwells. __3__ Addition of HRP-labeled SARS-CoV-2 antigen. ___4___ Addition of the substrate TMB into the microwells. __5__ TMB turns blue in IgM positive samples. __6__ Addition of stop solution. __7__ TMB turns yellow in IgM positive samples, due to the acidity of the stop solution. __8__ Read the absorbance at 450 nm with a microplate reader
An enzyme that is catalytically efficient will have: a) a low VMAX and a high KM b) a blocked active site c) the same VMAX and KM d) a high VMAX and a low KM
a high VMAX and a low KM
The OD260/OD280 ratio of a DNA sample is 1.96. The DNA sample is most likely ______. - cannot be predicted - contaminated by protein - a pure sample of DNA - contaminated by RNA
a pure sample of DNA
What would be the matching strand to the following palindromic sequence: 5'-GGATCC-3' a) 3'-CCTAGG-5' b) 3'-GGATCC-5' c) 5'-GGATCC-3' d) 5'-CCTAGG-3'
a) 3'-CCTAGG-5'
We know that the PCR steps are carried out at different temperatures. At what temperature does the denaturation step occur? a) 94 °C b) 55 °C c) Any temperature d) 72 °C
a) 94 °C
Restriction Enzymes are isolated from: a) Bacteria b) Fungi c) Protozoa d) Virus
a) Bacteria
In sequential order, which are the three steps of PCR? a) Denature DNA, Anneal Primers, Extend DNA b) Anneal Primers, Denature DNA, Extend DNA c) Denature DNA, Extend DNA, Anneal Primers d) Extend DNA, Anneal Primers, Denature DNA
a) Denature DNA, Anneal Primers, Extend DNA
Interpret the results (two lines present; at C and IgM) a) IgM positive b) IgG and IgM positive c) IgG positive d) Negative e) Invalid
a) IgM positive
BamHI, HindIII, and EcoRI are all examples of a) Restriction enzymes. b) Genes. c) DNA ligands. d) Southern blots.
a) Restriction enzymes.
The rate of any reaction is controlled by all of these except: a) These are all things that can control the rate of any reaction b) Substrate concentration c) Temperature d) pH e) Concentration of cofactors f) Enzyme concentration g) Presence of activator/inhibitor
a) These are all things that can control the rate of any reaction
Which option BEST describes sticky ends: a) Sticky ends are DNA fragments cleaved by a restriction enzyme so that both strands are the same length. b) Sticky ends are DNA fragments cleaved by a restriction enzyme so that one strand is longer than the other. c) Sticky ends are DNA fragments that carry a higher charge than normal after they have been cleaved by restriction enzymes. d) Sticky ends are DNA fragments that attract a carbohydrate molecule to one end after being cleaved by a restriction enzyme.
b) Sticky ends are DNA fragments cleaved by a restriction enzyme so that one strand is longer than the other.
How would the ten-fold decrease in enzyme concentration affect the observed Km? a) The KM will increase ten fold. b) The KM will be unchanged. c) The KM will decrease ten fold. d) The KM will have to be recalculated from the new data.
b) The KM will be unchanged.
To study the inhibitors/activators on reaction rate, we have used: a) inhibitor/activator, PEP, enzyme, without ADP b) inhibitor/activator, enzyme, ADP, PEP c) PEP, enzyme, ADP, without inhibitor/activator d) inhibitor/activator, ADP, PEP, without enzyme
b) inhibitor/activator, enzyme, ADP, PEP
You have isolated the enzyme Milleniase from the rare Y2K bug. This enzyme cleaves the first two numbers off of four digit dates. You flex your skills as an enzymologist and come up with the following graph of initial velocity as a function of substrate concentration: From the graph, estimate KM.( min:5, Max:35) a) 35 b) 17 c) 7 d) 5
c) 7
Restriction enzymes a) Stop transcription. b) Bind RNA fragments together. c) Cut DNA at specific sites. d) Bind together strands of DNA.
c) Cut DNA at specific sites.
Choose the correct representation of an enzyme and what it does, where E= enzyme, S= substrate, and P= product a) None of these b) E+S → E • S ⇄ E + P c) E+S ⇄ E • S → E + P d) E + S ⇄ E • S = E + P
c) E+S ⇄ E • S → E + P
The spike protein on the 3 different coronaviruses... a) Functions to allow the virus to be transmitted b) Functions to allow the virus to invade bacterial cells c) Functions to allow the virus into the host cells d) Functions to allow the virus to float in the air
c) Functions to allow the virus into the host cells
You are a research scientist studying a novel enzyme X, and you want to characterize this new enzyme. You measure the velocity of the reaction with different substrate concentrations and get the following data: [substrate] (mM) | Velocity (mmol/min) 3.0 10.4 5.0 14.5 10.0 22.5 30.0 33.8 90.0 40.5 Given these data, choose the correct graph a) Graph B b) Graph A c) Graph C d) Graph D
c) Graph C
In a sequence alignment result, a : (colon) indicates that --------- a) The amino acids aligned at the sites marked with the symbol are identical. b) The amino acids aligned at the sites marked with the symbol are weakly similar. c) The amino acids aligned at the sites marked with the symbol are strongly similar d) The amino acids aligned at the sites marked with the symbol are different.
c) The amino acids aligned at the sites marked with the symbol are strongly similar
If a plasmid has 2 BamHI single restriction sites, how many DNA fragments would be produced? a) Four b) Three c) Two d) One
c) Two
Electrophoresis is used to _____. a) separate fragments of DNA according to charge b) cut DNA into fragments c) separate fragments of DNA according to size d) amplify small DNA samples to obtain enough for analysis
c) separate fragments of DNA according to size
Sort the size (bp) of DNA fragments on this gel from small to large. 1 = smallest and 4 = largest. __2__C __3__B __4__A __1__D
closest to the - is largest, closest to the + is smallest
How many copies of target gene strand will you have after three cycles a) 32 b) 4 c) 8 d) 16
d) 16
Which spike protein sequences were used to identify key amino acid clusters responsible for evolving SARS-CoV-2? a) Rabit coronavirus, SARS-CoV-1 and SARS-CoV-2 b) Mouse coronavirus, SARS-CoV-1 and SARS-CoV-2 c) Rat coronavirus, SARS-CoV-1 and SARS-CoV-2 d) Bat coronavirus, SARS-CoV-1 and SARS-CoV-2
d) Bat coronavirus, SARS-CoV-1 and SARS-CoV-2
What website was used to compare the amino acid sequences? a) NCBI b) iCollege c) FASTA d) Clustal Omega
d) Clustal Omega
Restriction Enzymes were primarily used as: a) Defense by Protozoa against antibiotics b) All are correct c) Tool by Virus to cleave Bacterial genome d) Defense by Bacteria against bacteriophages viruses
d) Defense by Bacteria against bacteriophages viruses
What is the best combination of Vmax, KM for enzymes? a) High Vmax, High KM b) Low Vmax, Low KM c) Low Vmax, High KM d) High Vmax, Low KM
d) High Vmax, Low KM
Interpret the results (no lines present at all) a) Negative b) IgG and IgM positive c) IgM positive d) Invalid e) IgG positive
d) Invalid
The purpose of the reaction buffer (Tris-HCl, KCl, and MgCl2) in the PCR mixture is to: a) it includes the dNTPS b) Allow conductivity of DNA to move from the cathode to the anode c) Provide the DNA template for Taq polymerase to bind to d) Provide a stable environment (pH, ions, cofactors) for Taq polymerase
d) Provide a stable environment (pH, ions, cofactors) for Taq polymerase
In gel electrophoresis we use Gelstar reagent to a) To denature DNA b) Track the DNA while DNA runs c) Make the DNA dense, so they will sink to the bottom of the well d) Stain the DNA in order to visualize them under UV light
d) Stain the DNA in order to visualize them under UV light
How would the ten-fold decrease in enzyme concentration affect the observed Km? a) The KM will have to be recalculated from the new data. b) The KM will decrease ten fold. c) The KM will increase ten fold. d) The KM will be unchanged.
d) The KM will be unchanged.
In a sequence alignment result, an * (asterisk) indicates that --------- a) The amino acids aligned at the sites marked with the symbol are weakly similar. b) The amino acids aligned at the sites marked with the symbol are different. c) The amino acids aligned at the sites marked with the symbol are strongly similar d) The amino acids aligned at the sites marked with the symbol are identical.
d) The amino acids aligned at the sites marked with the symbol are identical.
When a typical restriction enzyme cuts a DNA molecule, the cuts are staggered so that the DNA fragments have single-stranded ends. This is important in recombinant DNA work because _____. a) only single-stranded DNA segments can code for proteins b) the single-stranded ends serve as starting points for DNA replication c) it allows a cell to recognize fragments produced by the enzyme d) the fragments will bond to other fragments with complementary single-stranded ends
d) the fragments will bond to other fragments with complementary single-stranded ends
Which of the following is NOT a dNTP used for PCR? a) dGTP b) dUTP c) dCTP d) dATP e) dTTP
dUTP
A DNA has too much protein contamination, the OD260/OD280 ratio of the sample will be ______. - higher than 1.8 - lower than 1.8 - 1.8 - lower than 0.8
lower than 1.8
Molarity (M) is measured in what units? - L/mol - mol/L - mol/mL - g/L
mol/L
Positive and negative controls are necessary in experiments because they... a) provide a standard for the outcomes of the experimental sample being tested b) none of the above c) add additional samples to the experiment d) make the experiment easier to complete
provide a standard for the outcomes of the experimental sample being tested
Fill in the blank: An * (asterisk) indicates amino acid positions which all have the _____ ______ amino acid for every protein.
same
Fill in the blank: A : (colon) indicates amino acid positions that have amino acids with _____ molecular properties
strongly similar
When using a micropipette, if you push to the second stop to fill it you will get ______. - the correct amount of solution - too little solution - too much solution - either too much or too little solution
too much solution
A phylogenetic tree allows us to compare the relatedness of different organisms based on certain characteristics. True False
true
ACE2 is a human receptor found primarily in the lungs and functions to manage blood pressure. True False
true
Adding ammonium sulfate decreases protein solubility causing the protein to aggregate and eventually fall out of solution. True False
true
During ion-exchange chromatography, samples that had the highest protein concentration were saved. These samples were then analyzed further and prepared for SDS-PAGE. - True - False
true
Fill in the blank: A . (period) indicates amino acid positions that have amino acids with ____________ molecular properties
weakly similar
The slope of a standard curve of Abs vs [protein] is equivalent to which Lambert-Beer variable? - OD - ε - c - D
ε