Bio 2010 - Microbiology » Spring 2023 » Lecture Exam 3

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Question #1
Why is oxygen necessary in aerobic cellular respiration?
A.   it is needed for glycolysis, which begins the process of respiration in cells.
B.   it is the final electron acceptor in the electron transport chain.
C.   it provides the hydrogen nuclei needed to create a proton gradient outside of the cell
D.   it is important in creating oxaloacetic acid in the Krebs cycle.
Question #2
What phase of cellular respiration has the highest ATP yield?
A.   oxidative phosphorylation
B.   glycolysis
C.   the transition reaction
D.   fermentation
E.   the Kreb's cycle
Question #3
Dinitrophenol (DNP) is a drug that has the ability to separate the flow of electrons through the electron transport and ATP proton pumps, used during the electron transport system. This means that the energy from electron transfer cannot be used for ATP synthesis. Assuming your bacteria has consumed DNP, how many ATPs would they produce form the complete, aerobic oxidation of one glucose molecule?
A.   38
B.   2
C.   0
D.   4
Question #4
The proton motive force is:
A.   the accumulation of water formed in respiration
B.   a H+ electrochemical gradient formed across the plasma membrane
C.   ATP accumulation in the plasma membrane
D.   the movement of flagella
E.   the movement of water across a membrane
Question #5
In the final step of the electron transport system, the rotation of the proton pump provides the energy for ATPase to enzymatically make ATP. What specifically is responsible for rotating this pump?
A.   Proton motive force from income CO2
B.   Proton motive force from incoming H+ ions
C.   Proton motive force from incoming ATP
D.   Proton motive force from incoming O2
Question #6
Which of the following statements is an accurate description of what happens in electron transport?
A.   NADH and FADH are reduced.
B.   The final electron acceptor is oxidized.
C.   The electrons gain energy with each transfer in the chain.
D.   NADH and FADH are oxidized.
Question #7
What is the difference between a reversible and non-reversible, competitive inhibitor?
A.   both permanently attaches to the enzymes active site
B.   reversible temporarily attaches to the enzymes active site
C.   both permanently attaches to the enzymes allosteric site
D.   neither one attaches to any location on an enzyme
Question #8
Which of the following does NOT directly affect the activity of an enzyme?
A.   oxygen concentration
B.   temperature
C.   pH
D.   substrate concentration
Question #9
How does extreme temperature affect mesophilic proteins?
A.   destroys products
B.   destroys substrates
C.   breaks chemical bonds
D.   preserves existing chemical bonds
Question #10
Substrates and enzymes capable of interacting to form products in a chemical reaction, must first overcome a thermodynamic barrier known as the reaction's:
A.   activation energy.
B.   equilibrium point.
C.   endothermic level.
D.   free-energy content.
E.   entropy.
Question #11
An oxidation enzymatic reaction is a reaction that:
A.   increases the pH
B.   decreases the temperature
C.   loses an electron
D.   gains an electron
Question #12
Which of the following best describes enzyme saturation?
A.   enzymes active site is not occupied by anything
B.   enzymes active site is occupied by O2
C.   enzymes active site is occupied by substrate
D.   enzymes active site is occupied ATP
Question #13
Microbial fermentation can be detected in laboratory identification by observing a change in:
A.   glucose levels
B.   oxygen levels
C.   pH
D.   temperature
Question #14
Fermentation pathways make ATP and NADH. The ATP is used for a variety of cell functions. Why do fermenting cells need to make NADH?
A.   to make less toxic final products
B.   to make more toxic final products
C.   to use in the transition reaction
D.   to use in the Kreb's cycle
E.   to use in the Electron Transport System
Question #15
Which of the following statements regarding glycolysis is FALSE?
A.   oxidation of glucose is complete
B.   oxidation of glucose yields pyruvic acid
C.   oxidation of glucose yields NADH
D.   oxidation of glucose yields ATP
Question #16
ATP is an energy rich molecule because:
A.   the bonds between the phosphate groups are unstable.
B.   the sugar in ATP has numerous carbon-hydrogen bonds.
C.   the three phosphate groups are strongly attracted to each other.
D.   the bonds between the phosphate groups are very stable.
Question #17
Pyruvic acid cannot advance into the Krebs cycle. It must first be converted into a product that can be further oxidized in Krebs cycle. What is the name of this transformed molecule that starts Krebs cycle?
A.   acetyl CoA
B.   CO2
C.   NAD+
D.   oxaloacetic acid
E.   phosphoglyceric acid
Question #18
Which of the following is NOT a similarity that BOTH the Kreb's and the Calvin Benson cycle share, or have in common?
A.   both cycles produce ATP
B.   both cycles have more than one chemical reaction
C.   both cycles oxidize compounds
D.   both cycles recycle their final products
E.   both cycles can start and stop
Question #19
Pyruvic acid, the end product of glycolysis, enters the citric acid cycle after it has been converted to:
A.   NADH.
B.   oxaloacetic acid.
C.   citric acid.
D.   none of these.
E.   acetyl-CoA.
Question #20
The Kreb's cycle completes two full turns for the oxidation of all pyruvic acid from glycolysis. How many total NADH molecules are made from Krebs cycle reactions only?
A.   4
B.   8
C.   0
D.   6
E.   2
Question #21
Which of the following is a Photosystem II specific product?
A.   ATP
B.   phosphogyceric acid
C.   NADPH
D.   CO2
E.   Glucose
Question #22
Which of the following is released as a photosynthesis byproduct or waste product?
A.   carbon
B.   water
C.   oxygen
D.   carbon dioxide
Question #23
A photosynthetic bacteria is exposed to a toxin that destroys NADPH. The levels of RuBP and glucose should:
A.   glucose increases and RuBP decreases
B.   both decrease
C.   both increase
D.   RuBP increases and glucose decreases
Question #24
During the reduction phase of the Calvin-Benson cycle, phosphoglyceric acid is ultimately reduced in order to make:
A.   phosphoglyceraldehyde; NADP & H+
B.   ribulose 1,5 รข bisphosphate (RuBP); NADP+ & H+
C.   phosphoglyceraldehyde; ATP
D.   pyruvic acid; NADP+ & H+
Question #25
In eukaryotes, gene expression is primarily regulated at the level of:
A.   translation
B.   transcription
C.   protein synthesis
D.   replication
Question #26
Which of the following statements is TRUE regarding gene regulation in bacteria?
A.   repressor proteins block transcription by binding to operator sequences.
B.   activator proteins bind near promoters and increase efficiency of translation.
C.   genes with related functions are often grouped together and have a single start codon.
D.   enhancers are commonly used to regulate transcription.
E.   small-molecule sensors usually bind DNA and change its 3D structure allosterically.
Question #27
Transcription of the structural genes in an inducible operon:
A.   does not result in the production of enzymes.
B.   starts when the pathway's substrate is present.
C.   stops when the pathway's product is present.
D.   occurs continuously in the cell.
E.   starts when the pathways product is present.
Question #28
The lactose operon is likely to be transcribed when:
A.   there is more glucose in the cell than lactose.
B.   the cyclic AMP levels are low.
C.   there is glucose but no lactose in the cell.
D.   the cAMP level is high and the lactose level is low.
E.   the cyclic AMP and lactose levels are both high within the cell.
Question #29
The lac operon genes only become expressed if:
A.   lactose binds to the operator
B.   glucose binds to the repressor
C.   the repressor binds to the operator
D.   lactose binds to the repressor
Question #30
Genes transferred from one cell to another is called:
A.   gene transfer
B.   horizontal gene transfer
C.   transfer of gene
D.   vertical gene transfer
Question #31
Bacterial conjugation is an example of:
A.   vertical gene transfer
B.   bacterial transformation
C.   horizontal gene transfer
D.   transduction
Question #32
In Griffith's experiments, the transforming substance was:
A.   RNA
B.   DNA
C.   proteins
D.   enzymes
Question #33
The transfer of genetic material between two bacteria in direct physical contact through the use of a pilus is called:
A.   conjugation
B.   transformation
C.   vertical gene transfer
D.   transduction
Question #34
Which of the following mutations results in a non-functional protein because a stop codon appeared too early in the mRNA sequence?
A.   frameshift
B.   missense
C.   nonsense
D.   silent
Question #35
Original DNA sequence: ATC CAT Mutated DNA sequence: ATC GCAT. What type of mutation occurred?
A.   silent
B.   insertion
C.   point mutation
D.   deletion
Question #36
A nonsenese mutation is a point mutation, usually in the second nucleotide position, and does which of the following?
A.   deletes the entire protein
B.   changes one single amino acid
C.   creates a new protein
D.   eliminates the start codon
E.   introduces a stop codon
Question #37
A type of substitution in which no amino acids change is called:
A.   nonsense
B.   silent
C.   missense
D.   Deletion
Question #38
Where does the energy come from to replicate complimentary copy DNA strands?
A.   electrical charge attraction
B.   dNTP' s
C.   kinetic charge attraction
D.   osmosis
E.   diffusion
Question #39
DNA molecules are made up of subunits called nucleotides. How many different types of nucleotides are used to make DNA molecules?
A.   one type
B.   three types
C.   four types
D.   two types
Question #40
All of the following are true statements concerning DNA structure, EXCEPT:
A.   the two strands of a DNA molecule are held together by hydrogen bonds.
B.   DNA contains the nitrogenous bases A, C, G, and U.
C.   the two strands of a DNA molecule are antiparallel to each other.
D.   DNA contains the sugar deoxyribose.
Question #41
Which enzyme unzips or separates the DNA helix in order to expose the two parental DNA strands and creates a replication fork?
A.   DNA helicase
B.   DNA ligase
C.   DNA polymerase
D.   DNA gyrase
Question #42
There are 64 codons and 20 amino acids. Which of the following is true?
A.   Several different codons can specify the same amino acid.
B.   Each amino acid is specified by only one codon.
C.   Some amino acids have no link to a codon.
D.   Each codon specifies a different amino acid.
Question #43
Which of the following is the best description of a gene?
A.   the entire DNA molecule
B.   a sequence of amino acids in a protein
C.   a single nucleotide
D.   a sequence of DNA nucleotides that codes for a single protein
Question #44
In our lecture, I compared condons to:
A.   words of a language
B.   stars in the universe
C.   people on the bus
D.   MnMs in a bag of candy
Question #45
If ATCG is the triplet DNA code, then the ANTICODON would be:
A.   TAGC
B.   AUGC
C.   UAGC
D.   UTGC
Question #46
  
A.   a sugar
B.   a protein
C.   an amino acid
D.   a lipid

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