MCB 2610 Wiley Assignment Questions
True or False: Most bacteria are larger than eukaryotes but smaller than viruses.
False
Which one of the following is an advantage to studying genetics in bacteria?
Only one copy of each gene is present on the bacterial chromosome
What are the advantages and disadvantages of growing in an oxygen-rich environment?
Oxygen, which is an avid acceptor of electrons, enables organisms to extract more energy from compounds via oxidative phosphorylation than can be extracted using any other terminal electron acceptor.
How does heat work to eliminate microbes from a substance?
Heat causes proteins to denature.
rRNA is a good molecule to generate phylogenetic relationships among species because ...
it is found in all known cells and is highly similar among all organisms.
In which phase of the growth curve does preparation for cell division and synthesis of enzymes needed for catabolic activity take place?
lag phase
Media used to grow microorganisms can be in _____.
liquid and solid forms
The best method for enumerating microbes present in a low density environment, such as a pond, would be ...
membrane filtration
How does MutH recognize which strand of the DNA is the newly synthesized strand?
methylation
What types of mutations can base substitutions form?
missense
Based on the concept of the decimal reduction time (D value), a larger starting population of bacteria ...
would require more D values to reduce the population to one microbe than a smaller population.
How does archaeal pseudomurein structurally differ from bacterial peptidoglycan in cell walls?
ß-1,3-glycosidic bonds link sugar derivatives in pseudomurein.
Which of the following is not a characteristic that distinguishes living organisms from nonliving? (A) DNA as the genetic material (B) Metabolism (C) Growth (D) Reproduction
(A) DNA as the genetic material
Which of these is the most widely used form of energy in cell processes?
ATP
What is/are the product(s) of the light reactions of photosynthesis?
ATP and NADPH
ABC transporters use what mechanism to transport molecules across the plasma membrane?
ATP hydrolysis
What is meant by the phrase "The genetic code is degenerate"?
An amino acid is specified by more than one codon.
What is a plasmid?
An extrachromosomal molecule of DNA
Which metabolic pathway is the most energy efficient?
Anaerobic respiration
What is the major difference between DNA in bacteria and archaea?
Archaea have histones, bacteria do not
How does the plasma membrane differ in composition between archaea and eukarya/ bacteria?
Archaeal membranes are made of isoprenoids connected to glycerol 1-P.
How are archaea and eukaryal cells similar?
Archaeons are more similar to eukaryotes in the manner they conduct transcription, translation and DNA replication.
How are archaeons similar and different from bacteria?
Archaeons are similar to bacteria in morphology, size and in the size of their genomes. Like bacteria, the archaeons lack a membrane-bounded nucleus to contain their genomes.
Which of the following is a microorganism?
Bacteria
What are the three domains of life?
Bacteria, Archaea, and Eukarya
What is one difference between bacterial and archaeal flagella?
Bacterial flagella are made up of one subunit; archaeal flagella are made up of multiple subunits
Extremophiles are all anaerobic.
False
True or False: All 20 amino acids can be synthesized from precursor molecules drawn from the TCA cycle and photosynthetic pathway.
False
True or False: All Archaea are extremophiles.
False
True or False: Bacteria do not evolve because they do not engage in sexual reproduction.
False
True or False: Horizontal gene transfer is the movement of RNA between bacteria whereas vertical gene transfer is the inheritance of a gene from any ancestor.
False
True or False: Mutations are deleterious changes to DNA sequences
False
True or False: Pasteurized milk is sterile.
False
True or False: The appearance of plants in evolutionary history led to the abundance of molecular oxygen in the atmosphere and the rise of aerobic organisms.
False
True or False: When referring to nucleic acids, antiparallel means the two strands of DNA take on a helical configuration rather than a linear, parallel configuration.
False
What role does crosslinking of the peptidoglycan molecules play in cell structure?
Gives strength to the peptidoglycan network
Some anoxygenic photosynthetic bacteria are able to use _______ as an electron source.
H2S
What is the term for microbes that grow optimally at very high salt concentrations?
Halophiles
What is the electron donor in oxidative phosphorylation?
NADH
Why does anaerobic respiration produce less ATP than aerobic respiration?
O2 is a stronger oxidation agent than other terminal electron acceptors.
Which organisms do not possess defenses against oxidative damage, such as catalases and superoxide dismutase?
Obligate anaerobes
What is the difference between phenotypic selection and screening?
Phenotypic selection only allows mutants with a particular phenotype to survive, in screening, everything survives but mutants have a different phenotype.
An organism that uses light energy and inorganic chemicals for their carbon, energy and electron sources is a ...
Photolithoautotroph
Cyanobacteria are the only group of bacteria to produce oxygen from photosynthesis because no other groups of photosynthetic bacteria ...
Split water to generate electrons.
Which of these are fossilized microbial mats containing photosynthetic bacteria?
Stromatolites
Histones have been found in both archaeal and eukaryal species. What is one difference between archaeal and eukaryal species?
There are two histones in archaeal species, four in eukaryal species
What did Griffith's experiments show?
There was a cellular factor that could alter the phenotype of R cells.
Although bacteria do not have membrane-bound organelles in their cytoplasm, they do have inclusion bodies such as polyhydroxybutyrate (PHB) and sulfur granules. Why would bacteria want to store these compounds?
These compounds are useful forms of energy.
How do organisms use sugars other than glucose for metabolism?
They break down more complex sugars into intermediates that can enter glycolysis.
Why can't eukarya initiate transcription in the middle of a mRNA?
They rely on the 5' cap for initiation
How do organisms use lipids to generate ATP?
They use β-oxidation to generate reduced electron carriers.
An individual colony visible on an agar plate is ...
a pile of millions of bacterial cells all descended from a single cell.
What would you use to measure the optical density of a bacterial culture?
a spectrophotometer
What does the term "mutant" refer to?
a strain that has a change in the DNA relative to wild-type strain
What kinds of genes are carried on plasmids?
accessory genes that provide non-essential functions
What is the term for microbes that grow optimally at a pH below 5.5?
acidophiles
Anoxygenic photosynthesis differs from oxygenic photosynthesis in that ...
anoxygenic photosynthesis does not produce oxygen, while oxygenic photosynthesis does.
Chemicals that can only be used externally to kill microbial pathogens on living tissues are called ...
antiseptics
The most effective way to sterilize most bacterial media is by ...
autoclaving
Although morphology is a consistent characteristic of most bacterial species, it is generally not the definitive character for differentiating among species because ...
bacterial shapes can be impacted by cultural and environmental conditions
Why is O2 a good final electron acceptor?
because O2 is a strong oxidant
When attempting to cultivate a bacterial species that has not previously been grown in a laboratory ...
both nutritional and environmental factors must be considered.
How do chemolithotrophs generate ATP?
by coupling oxidation of an inorganic source to oxidative phosphorylation
Because many pharmaceutical products are heat-sensitive, they are sterilized ...
by ionizing radiation
How did Pasteur disprove spontaneous generation?
by showing that bacteria would only grow when in direct contact with bacteria in the outside air
Proteins are useful as secondary nutrient sources because they ...
can be fermented to generate energy.
Unlike bacteria, the cytoplasmic membrane of many archaea ...
can exist as a monolayer.
This structure protects a bacterium from phagocytosis.
capsule
An advantage of using rRNA to identify bacteria is ...
cells don't have to be cultured first.
Generally, bacterial DNA is _____ while eukaryal DNA is _____.
circular; linear.
An important finding from Edward Jenner's vaccination experiment ....
immunity to one microorganism can be conferred by exposure to a closely related microorganism.
Catabolism is referred to as ...
the breakdown and oxidation of larger molecules.
To achieve stability in a continuous culture system ...
the dilution rate must be less than the maximal growth rate so that cell numbers can be replenished before being washed out with excess media.
Gibbs free energy is a measure of...
the energy released or consumed in a chemical reaction.
What is meant by the term "feedback inhibition"?
the final product of a pathway can inhibit enzymatic activity of the enzymes early in the process
The generation time of a bacterial species is determined by measuring the change in population size over time during ...
the log phase of growth.
Which cellular structure is chemically different in archaea as compared to bacteria and eukarya?
the plasma membrane
What is proton motive force?
the potential difference between the inside and outside of the membrane.
What does a gradient of transfer tell you?
the relative location of a gene on a chromosome
What does the redox potential measure?
the tendency of a molecule to acquire electrons
Which of the following is true of enzymes?
they are not used up in a chemical reaction
Why are β-lactam antibiotics effective in killing bacteria?
they interfere with peptidoglycan crosslinking and weaken the cell wall
Light repair uses an enzyme to break the harmful covalent bonds between _____ and _____.
thymine: thymine
What is the role of a photosystem?
to absorb the energy from light and transfer it to an associated electron transfer chain
What is the role of photosystem?
to absorb the energy from light and transfer it to an associated electron transfer chain
What is the role of DnaA in DNA replication?
to bind to the origin and begin strand separation
What is the role of chlorophyll in photophosphorylation?
to capture photons
What is the role of ParM proteins in bacterial cell division?
to move copies of plasmid DNA molecules to the opposite ends of the bacterial cell
In aerobic respiration, there are three points along the electron transport chain which are accompanied by significant decreases in free energy. This free energy is used directly to ...
to pump H+ across membranes to create a proton motive force.
In the Miller-Urey experiment, why was the flask of water boiled?
to stimulate early planetary conditions
What is the importance of the reductive TCA cycle?
to synthesize metabolic intermediates and acetyl-CoA for biosynthetic reactions
What is substrate level phosphorylation?
transfer of a phosphate group from a substrate to ATP
What is a wild-type strain?
typically refers to strain isolated from nature
How did the atmospheric O2 concentration rise?
via cyanobacteria
True or False: Viruses do not meet the commonly held definition for living organisms.
True
Vaccination has been practiced in various parts of the world for thousands of years.
True
True or false: ribosomes are associated with the DNA.
True: transcription and translation are co-localized in bacteria
What does the phrase "bacterial genomes are genetically compact" mean?
Most of the bacterial genome codes for proteins
What is the result of semiconservative replication of DNA?
The replicated DNA contain one new and one old DNA strand
During diffusion, molecules move from an area of ___ concentration to ___ concentration.
high : low
True or False: Differential media can used to distinguish among the different types of hemolytic activity.
True
What is the role of MreB?
determination of cell shape
Which of the following statements best describes the "great plate anomaly"? (A) The number of cells microscopically visible in a sample greatly exceeds the number of colonies that grow when the sample is plated on an agar plate (B) The number of colonies that grow when a sample is plated on an agar plate greatly exceeds the number of cells microscopically visible in the sample (C) When agar plates are incubated at 37oC, colonies always are larger than when agar plates are incubated at 20oC (D) When agar plates are incubated at 20oC, colonies are larger than when agar plates are incubated at 37oC
(A) The number of cells microscopically visible in a sample greatly exceeds the number of colonies that grow when the sample is plated on an agar plate
Which of the following is TRUE regarding chemoheterotrophs? (A) They acquire energy and electrons from organic compounds (B) They acquire energy from inorganic compounds (C) They use carbon dioxide as their carbon source (D) They acquire electrons from inorganic compounds
(A) They acquire energy and electrons from organic compounds
Which of the following is NOT likely to be true of primitive microbes? (A) They were aerobic (B) They were photosynthetic (C) They could survive in acidic conditions (D) They had a plasma membrane
(A) They were aerobic
Which of the following is NOT found in RNA? (A) Uracil (B) Deoxyribose (C) 5' phosphate (D) Adenine
(B) Deoxyribose
Which of the following is not a law of thermodynamics? (A) Energy is conserved in a chemical reaction (B) Energy is used up in a chemical reaction (C) Energy can be converted from one form to another (D) Energy flows from an ordered state to a less ordered state
(B) Energy is used up in a chemical reaction
Which of the following statements is INCORRECT? (A) F stands for fertility. (B) F+ refers to recipient strains. (C) The F plasmid is a very large, circular dsDNA plasmid. (D) When transferred by conjugation from an F+ cell, the F plasmid converts an F- cell lacking the plasmid to an F+ cell. (E) The F plasmid contains all the genes needed for conjugation and plasmid maintenance in the cell.
(B) F+ refers to recipient strains.
Which of the following is a component of the cytoplasm found only in bacterial cells? (A) Ribosomes. (B) Magnetosomes. (C) Gas vesicles. (D) Proteins.
(B) Magnetosomes.
Which of the following is the INCORRECT function of a spectrophotometer in regards to bacterial cultures? (A) The greater the transmittance of a bacterial culture, the lower the bacterial concentration (B) The greater the transmittance of a bacterial culture, the greater its optical density (C) The greater the absorbance of a bacterial culture, the higher the bacterial concentration (D) The greater the absorbace of a bacterial culture, the greater its optical density
(B) The greater the transmittance of a bacterial culture, the greater its optical density
Microbes are useful models for research for several reasons. Which of the following reasons is INCORRECT? (A) Many microbes can grow rapidly on inexpensive media and be genetically manipulated quite easily. (B) They are difficult to cultivate in the lab. (C) Many of them have metabolic and regulatory pathways that are very similar to those found in more complex organisms (e.g., complex eukaryotes). (D) They can be used for large-scale production of chemical compounds and useful macromolecules.
(B) They are difficult to cultivate in the lab.
Which of the following may be a function of proteins within a cell? (A) To be a polypeptide (B) To catalyze chemical reactions (C) To provide instructions for assembly of polypeptides (D) Energy storage
(B) To catalyze chemical reactions
Which of the following is NOT a characteristic of life? (A) Respond to stimuli (B) evolution (C) Being multicellular (D) homeostasis
(C) Being multicellular
Escherichia coli is inoculated in tryptic soy broth and grows well overnight. Please indicate which statement is NOT true. (A) All of the nutrients required for E. coli growth are available. (B) When agar is added to tryptic soy broth, E. coli will still grow. (C) Colonies can be identified from the tryptic soy broth grown overnight. (D) Other bacteria with the same nutrient requirements will grow in the tryptic soy broth.
(C) Colonies can be identified from the tryptic soy broth grown overnight.
Which of the following is not one of Koch's postulates? (A) The microbe must be found in all organisms with the disease, and absent from all organisms without the disease. (B) When inoculated into a susceptible host, the microbe must cause the disease. (C) The microbe must be re-isolated from experimentally infected hosts and injected into a another host to be sure it is still infectious. (D) The microbe must be isolated and cultured in the lab.
(C) The microbe must be re-isolated from experimentally infected hosts and injected into a another host to be sure it is still infectious.
Select the INCORRECT statement regarding the reason why microbes do not generally grow in salty environments (A) they reduce water availability for microbe use (B) they increase osmotic stress for the microbe (C) they cause water to rush into the microbial cell, resulting in cell lysis (D) they decrease water activity (aw) in the environment
(C) they cause water to rush into the microbial cell, resulting in cell lysis
How is ATP used within the cell? (A) Hydrolysis of the phosphoanhydride bonds releases energy that can be used to power chemical reactions. (B) Phosphorylation of ADP stores energy that can be used later to power chemical reactions. (C) As an energy currency in the cell. (D) All of these choices
(D) All of these choices
How do vaccines work? (A) by exposing an individual to a weakened version of a microbe to cause a person to have immunity. (B) by exposing an individual to a small piece of a microbe to cause a person to have immunity. (C) exposing an individual to an inactivated version of a microbe to cause a person to have immunity. (D) All of these choices are correct.
(D) All of these choices are correct.
In bacterial cells, you are likely to find which of the following molecules closely associated with the nucleoid of the cell? (A) DNA polymerase. (B) RNA polymerase. (C) RNA. (D) All of these choices.
(D) All of these choices.
Which of the following is a structural adaptation for life at high temperatures? (A) Lipid monolayers instead of bilayers. (B) Ether linkages instead of ester linkages. (C) Isoprenoids instead of fatty acids. (D) All of these choices.
(D) All of these choices.
Select the CORRECT statement regarding substitution mutation types. (A) Changes in codons that do not alter the amino acid sequence of the resulting protein are referred to as missense mutations. (B) Point mutations are those that alter the sequence of a protein because they result in a change in the specificity of a codon. (C) Silent mutations can lead to the conversion of an amino acid coding codon into a stop codon (thereby stopping the protein prematurely) are referred to as nonsense mutations. (D) Different types of mutations refer to how they affect the codons in the mRNA message and therefore the amino acid sequence of the polypeptide.
(D) Different types of mutations refer to how they affect the codons in the mRNA message and therefore the amino acid sequence of the polypeptide.
The products of the Embden-Meyerhof pathway are all of the following EXCEPT (A) ATP (B) Pyruvate (C) NADH (D) FADH2
(D) FADH2
Select the INCORRECT statement about the ways freezing food protects it from microbial spoilage? (A) Bacteria can't replicate at low temperatures (B) Biochemical reactions do not work efficiently at low temperatures (C) Ice crystals form in the foods and break open the microbial cells (D) It causes denaturation of bacterial proteins
(D) It causes denaturation of bacterial proteins
Which of the following is NOT a component of DNA? (A) 5' phosphate (B) 2-deoxyribose (C) Thymine (D) Uracil
(D) Uracil
Which is an effective method for sterilizing plastic items like test tubes and pipet tips? (A) Autoclave. (B) Gamma radiation. (C) Phenolic compounds.. (D) a and b.
(D) a (autoclave) and b (gamma radiation).
Peptidoglycan is made of which molecule? (A) N-acetylmuramic acid (NAM) (B) N-acetylglucosamine (NAG) (C) short peptide chains (D) all of these choices
(D) all of these choices
The cytoplasm of a bacterium contains which features? (A) DNA (B) ribosomes (C) cytoskeletal structures (D) all of these choices
(D) all of these choices
What structures are commonly referred to as the cell envelope? (A) plasma membrane (B) peptidoglycan layer (C) outer membrane (D) all of these choices
(D) all of these choices
Where do the precursors for most macromolecules come from? (A) The EMP pathway (B) The pentose phosphate pathway (C) The TCA cycle (D) all of these choices
(D) all of these choices
A bacterial cell's growth rate is ultimately determined by its ability to (A) acquire nutrients. (B) assemble monomers. (C) synthesize macromolecues. (D) all of these choices.
(D) all of these choices.
During the stationary phase of the bacterial growth curve, bacteria may respond to the environmental stress by (A) producing highly resistant endospores. (B) growing flagella. (C) becoming competent, capable of taking up pieces of naked DNA. (D) all of these choices.
(D) all of these choices.
Which of the following can NOT be used as an electron source for photophosphorylation? (A) H2O (B) H2S (C) H2 (D) oxygen
(D) oxygen
Which of the following can be broken down into smaller molecules? (A) Fats (B) Proteins (C) Carbohydrates (D) Nucleic acids (E) All of these choices
(E) All of these choices
Which of the following measures has been effective in controlling and reducing deaths from infectious diseases? (A) improved hygiene in healthcare settings. (B) discovery and widespread use of vaccines and the development of antibiotics. (C) improved public health measures including sewage treatment and garbage removal. (D) improved preparation and handling of food and water. (E) All of these choices are correct.
(E) All of these choices are correct.
Transcription is the process of ...
(m)RNA production
How long would it take a culture of E. coli with a starting cell density of 1 × 105 cells/ml to reach a cell density of 1 × 108 cells/ml if it had a generation time of 30 minutes?
5 hours
The general size ranges of bacteria are between ...
0.5 µm and 5 µm
Which of the following conditions are required to inactivate highly resistant bacterial endospores?
121oC at 15 p.s.i. for 15 minutes.
A broth culture was diluted 10-fold, 0.1 ml was spread onto an agar plate and 47 colonies were counted. What is the estimated cell concentration in the original broth culture?
4,700 cells/ml
Fresh media is inoculated with an actively growing Escherichia coli culture. You measure the optical density (OD) at the time of inoculation and record a value of 0.05. Two hours later you take another reading and record an optical density of 0.2. What is the generation time for your culture?
60 minutes
In order for a chemostat to operate properly, what must the reservoir contain?
A limiting nutrient
What is an auxotroph?
A mutant with a mutation in a metabolic pathway
What is a gene?
A stretch of DNA that is transcribed into RNA
What is a chemostat?
A system used for the continuous culture of microbial cells
Which of the following microbial control methods is a complete sterilization method?
Autoclaving
Why does the transfer of electrons through the electron transport chain generate proton motive force?
Because each complex along the electron transport chain has increasing redox potential
Why will a prototroph grow more slowly in an organic-poor environment?
Because synthesis of molecules necessary for growth takes longer than getting them from the environment
Why are Okazaki fragments made during DNA replication?
Because there is a leading and a lagging strand.
Which of the following properties is common to both photosystem I and photosystem II?
Both are excited by unique light wavelengths.
What is a similarity between Rho dependent and Rho independent termination of transcription?
Both cause the RNA polymerase to stall and fall off
How did Lister help decrease the number of hospital-acquired infections?
By developing an antimicrobial agent to use in hospitals
Who showed that you could expose a person to an inactivated or weakened version of a microbe, or even just a part of the microbe, to create immunity to a disease?
Edward Jenner
What is the idea behind replica plating?
Colonies are transferred from a master plate onto multiple different kinds of plates to determine phenotype
What is the likely origin of eukaryal mitochondria and chloroplasts?
Endosymbiosis of bacteria
Why are multiple origins of replication necessary for DNA replication in eukaryotes?
Eukaryal genomes are typically much larger than bacterial genomes, so multiple origins of replication ensures all the DNA is able to be replicated in a reasonable amount of time.
Hershey and Chase concluded that the hereditary material of bacteriophage T2 was ...
DNA
The cell walls of Archaea and bacteria ...
Differ in that Archaea cell walls contain pseudomurein instead of peptidoglycan
Select the correct sequence of taxonomic categories used to classify bacteria beginning with the highest rank.
Domain, phylum, class, order, family, genus, species
Why are really large prokaryal cells so rare?
Large cells with no internal membrane organization or division of labor are not efficient enough metabolically to survive.
This early microbiologist used a swan-necked flask to help disprove the Theory of Spontaneous Generation.
Louis Pasteur
Which bacteria (Auxotrophs vs. Prototrophs) can grow in any nutritional environment?
Prototrophs: they can synthesize anything they need.
Due to its versatility, many scientists have hypothesized this molecule may have formed the basis for early life on earth.
RNA
Transcription is ...
RNA synthesis from a DNA template.
Which of the following is true of cellular respiration?
Respiration fuels more ATP production per NADH regenerated than fermentation
What role does reversion play in studying auxotrophs?
Reversion changes the auxotroph so it can grow in a similar manner to wild type.
This scientist established a set of criteria to determine if a microbe is the cause of a specific disease.
Robert Koch
What sequence is the initiation sequence for bacterial translation?
Shine-Delgarno
What is oxidative phosphorylation?
Synthesis of ATP using the energy derived from a proton gradient that requires oxidation of a chemical substrate
Which of the following is not a function normally associated with cytoplasmic membrane proteins?
Synthesis of cytoplasmic membrane components.
Which of the following is necessary for termination of DNA replication in bacteria?
Ter sites
How is RNA different from DNA?
The sugar in RNA is a ribose whereas the ribose sugar in DNA lacks a hydroxyl group on the 2' carbon (it is 2-deoxyribose).
What is the role of DNA ligase in DNA replication?
To join short segments of DNA together
What is the role of DnaG in DNA replication?
To make RNA primer
What is the role of DnaG in bacterial DNA replication?
To make RNA primer
What is always an outcome of respiration?
To regenerate NAD+ while forming additional ATP
What is the role of DnaB in DNA replication?
To unwind DNA
What is the role of DnaB in bacterial DNA replication?
To unwind DNA
What is the role of bacteriophage in transduction?
Transfer bacterial DNA from one cell to another.
True or False: During the stationary phase of the bacterial growth curve, the number of cells being produced is equal to the number of cells dying.
True
True or False: Facilitated diffusion involves the use of transport proteins to move substances across the cell membrane.
True
True or False: In a typical bacterial growth curve, both the growth phase and the death phase are exponential.
True
True or False: Nucleotides, both purines and pyrimidines, are synthesized from precursor molecules drawn from the EMP pathway, the TCA cycle, and/or the pentose phosphate pathway.
True
True or False: One difference between DNA from eukaryal cells and DNA from bacterial cells is eukaryal cells use histones to pack their DNA while prokaryal cells use cations and some positively charged proteins.
True
True or False: Some bacteria produce hyphae composed of long chains of cells.
True
True or False: The expression of a gene (i.e. transcription and translation) could occur more quickly in a prokaryote compared to a eukaryote.
True
True or False: The generation time is the average time interval from one cell division to the next.
True
True or False: The hydrocarbon chains in bacteria and eukaryotes are linked to the glycerol phosphate molecule by ester linkages whereas the hydrocarbon chains in archaea are linked by ether bonds.
True
If a cell has an F plasmid, it can ...
conjugate and transfer DNA to a neighboring cell
What is photophosphorylation?
conversion of light energy to chemical energy
The role of an enzyme in a reaction is to ...
decrease the activation energy of a reaction
Alcohol works as a disinfectant by ...
dissolving and disrupting cell membranes.
Which of the following statements best describes fermentation?
electrons are passed directly from NADH to a terminal electron acceptor
Bacteria that use oxygen for respiration when it is present, but are able to grow in an anaerobic environment as well are ...
facultative anaerobes.
True or false: all bacteria disconnect from each other when they divide.
false, some bacteria completely disconnect from each other during cell division, some remain connected to each other
Phospholipids, important components of biological membranes, are composed of ...
fatty acids linked to a glycerol backbone.
What is the role of FtsZ?
formation of the Z ring
What types of mutations can base insertions or deletions form?
frameshift
Bacteria are able to occupy more habitats than eukaryal cells because they ...
have greater metabolic diversity
In the language of nucleic acids, sequences that are complementary ...
have nucleotides that form pairs, A with T and C with G.
Increasing temperature impacts bacterial cell function by ...
increasing fluidity but decreasing selectivity of the plasma membrane.
How does UV irradiation kill microbes?
induces DNA damage
Although prototrophic organisms can grow in nutrient poor habitats, growth is normally slow because ...
more time and energy is required for synthesis of amino acids and other metabolic precursors under nutrient poor conditions.
What cellular feature spatially and temporally separates transcription from translation in eukarya?
nuclear membrane
Chlorine, ozone, and iodine are all examples of ...
oxidizing agents
A/an ____ contains circular DNA and carries resistance genes.
plasmid
Which method allows for enumeration of only live cells?
plate counts
If the goal is to estimate the number of bacteria in a broth sample, the most appropriate separation technique would be the ...
pour plate
What is the initiation site for transcription?
promoter
What the initiation site for transcription?
promoter
Glycerol can be converted to ...
pyruvic acid
What is the single best piece of evidence that archaea are a separate domain from bacteria and eukarya?
rRNA sequence analysis
Which of the following is a function of the plasma membrane?
regulating substances in the cytoplasm through differential permeability
One characteristic that differentiates Archaea from Bacteria is ...
some archaea have regular geometric shapes like rectangles or squares.
All of the following are mechanisms for determining cell abundance except ...
streak plates
The ATP in the Embden-Meyerhof-Parnas pathway comes from ...
substrate-level phosphorylation.
Biofilms are ...
surface associated communities of one or more species of bacteria.
Which of the following is necessary for termination of DNA replication in eukarya?
telomeres
What was Esther Lederberg was able to demonstrate with her replica plating experiments?
that mutations can arise spontaneously without selective pressure
