Microbiology 154 Exam 1 Review Flashcards
Which of the following are required for microbial cell growth?
a. reduced cofactors
b. anabolic intermediates
c. energy conserved in chemical bonds
d. only (b) and (c)
e. (a), (b), and (c) are all required
e. (a), (b), and (c) are all required
Prokaryotes and eukaryotes.
a. have the same kinds of metabolic pathways, but little else in common
b. have nothing in common
c. have many things in common because they evolved from a common ancestor
d. are identical to each other
b. have nothing in common
The metabolism of microorganisms different from plants and animals because they
a. can only use oxygen as a terminal electron acceptor
b. can use any element as a terminal electron acceptor
c. can use various chemicals as terminal electron acceptors
d. do not require an electron acceptor
c. can use various chemicals as a terminal electron acceptor
?
Oxidative phosphorylation is made possible by
a. the use of oxygen to reduce NAD+
b. the use of inorganic molecules as a source of carbon
c. fermentation where inorganic compounds are used as a terminal electron acceptor
d. a proton gradient that is formed by an electron transport chain
e. answers (a), (b), and (c) are all correct
e. answers (a), (b), and (c) are correct
?
A bacterial species has a generation time of 20 minutes and is growing exponentially. If there is 10 cells initially how many cells are there after 80 minutes?
a. 30
b. 80
c. 160
d. 200
e. none of the above
c. 160
10*2^4=160
Fermentation occurs
a. as a result of oxidative phosphorylation
b. as a result of substrate level phosphorylation
c. when an organic compound is used as a terminal electron acceptor
d. only when there are no inorganic electron acceptors available
c. when an organic compound is used as a terminal electron acceptor
An electron transport chain in bacteria
a. ‘pumps’ protons outside the cell
b. creates a proton motive force
c. results in phosphorylation of ADP to form ATP
d. answers (b) and (c) are correct
e. answers (a), (b) and (c) are all correct
d. answers (b) and (c) are correct
The growth of almost all bacteria in the environment
a. is limited by cool temperatures
b. is limited by high pH
c. is limited by the availability of one or more nutrients
d. is unlimited because bacteria are metabolically versatile
d. is unlimited because bacteria are metabolically versatile
Pasteur used swan-necked flasks
a. to disprove the theory of spontaneous generation
b. to explain why wine was sometimes sour
c. to demonstrate the cause of rabies
d. to demonstrate the effectiveness of pasteurization
a. to disprove the theory of spontaneous generation
According to Koch’s postulates a microorganism thought to cause a disease in one species of animal
a. must be seen in samples of blood using a microscope
b. must be isolated in pure culture and then used to cause the same disease in healthy animals
c. must never be found in healthy individuals
d. all the above
c. must never be found in healthy animals
In efforts to understand the causes of disease Pasteur showed that pathogenic organisms could be transmitted
a. by direct contact with an infected individual
b. by failing to sterilize surgical instruments
c. through the air
d. by drinking contaminated water
c. through the air
Antoni van Leeuwenhoek developed and used
a. the first compound microscope
b. the first vaccine to prevent an infectious disease
c. a microscope with a single lens
d. pasteurization to prevent the spoilage of food
c. a microscope with a single lens
Which of the following statements is true?
a. the cell walls of most bacteria are composed of peptidoglycan
b. peptidoglycan is a fatty acid
c. Gram-positive bacteria have a relatively thin layer of peptidoglycan
d. peptidoglycan is found mainly in the cell walls of fungi, algae and plants
e. answers (a) and (c) are correct
a. the cell walls of most bacteria are composed of peptidoglycan
Gram positive bacteria
a. have a thick cell wall, which retains the crystal violet dye when cells are Gram stained
b. contain teichoic acid in their cell walls
c. appear purple when Gram stained
d. all the above
e. none of the above
d. all of the above
The cell envelope of Gram negative bacteria
a. includes a thick cell wall
b. includes both an inner and outer membrane
c. includes a peptidoglycan layer
d. always includes a capsule made of polysaccharides
e. answers (b) and (c) are correct
e. answers (b) and (c) are correct
The cell membrane of bacteria
a. is semi-permeable
b. is usually a lipid bilayer
c. prevents cell lysis due to high intracellular osmotic pressure
d. answers (a) and (b) are correct
e. answers (a) and (c) are correct
d. answers (a) and (b) are correct
Which of the following statements are true about metabolism of a carbon-containing substrate:
a. ADP is reduced to form A TP
b. NAD+ is reduced to form NADH
c. it is always completely oxidized to carbon dioxide
d. answers (a) and (b) are correct
e. answers (a), (b) and (c) are all correct
e. answers (a), (b), and (c) are all correct?
Chemoheterotrophs
a. use carbon dioxide as a carbon source
b. use organic compounds as a carbon source
c. use chemical compounds as an energy source
d. answers (a) and (c) are correct
e. answers (b) and (c) are correct
c. use chemical compounds as a energy source
As part of metabolism ATP is formed
a. only by substrate level phosphorylation
b. by both substrate level phosphorylation and oxidative phosphorylation
c. during anabolism
d. none of the above
b. by both substrate level phosphorylation and oxidative phosphorylation
?
Regarding early life on Earth,
a. microbial life existed for hundreds of millions of years before plant and animal life
b. microbial life existed long before animals but has been around for about the same amount of time as plants
c. microbial life, plant life, and animal life all appeared at about the same time
d. it is impossible to determine which type of life first appeared
a. microbial life existed for hundreds of millions of years before plant and animal life
The structure that confers structural strength on bacterial cells is known as the
a. cytoplasmic membrane
b. cell wall
c. ribosome
d. cytoplasm
b. cell wall
Archaea and Bacteria are unified as prokaryotes in lacking ______________
a. membranes
b. nuclei
c. membrane-enclosed organelles
d. nuclei and membrane-enclosed organelles
d. nuclei and membrane-enclosed organelles
What is the name of the process in which cells take up nutrients from the environment and convert them into new cell constituents and waste products?
a. cell signaling
b. metabolism
c. evolution
d. differentiation
b. metabolism
When a bacterial culture contains only one type of organism, it is called a ______________.
a. mixed culture
b. liquid culture
c. environmental culture
d. pure culture
d. pure culture
Most microorganisms are pathogenic.
a. True
b. False
b. false
Which of the following statements is true?
a. peptidoglycan is comprised of cross-linked fatty acids
b. the cell walls of most bacteria are composed of peptidoglycan
c. Gram-negative bacteria have a relatively thick layer of peptidoglycan
d. peptidoglycan is found mainly in the cell walls of fungi, algae and plants
e. answers (a) and (b) are both correct
e. answers (a) and (b) are both correct
In metabolism, microorganisms
a. can only use oxygen as a terminal electron acceptor
b. can use any element as a terminal electron acceptor
c. are different from plants and animals because they can use various chemicals besides
oxygen as a terminal electron acceptor
d. do not require an electron acceptor
c. are different from plants and animals because they can use various chemicals besides oxygen as a terminal electron acceptor.
The cell membrane of bacteria
a. is semi-permeable.
b. is usually a lipid bilayer
c. prevents cell lysis due to high intracellular osmotic pressure
d. answers (a) and (b) are correct
e. answers (a) and (c) are correct
d. answers (a) and (b) are correct
Oxidative phosphorylation of ADP to form ATP can occur as a result of
a. aerobic respiration wherein oxygen is used as a terminal electron acceptor
b. anaerobic respiration wherein other inorganic molecules (such as nitrate) are used as a
terminal electron acceptor
c. a proton motive force
d. all of the above
e. none of the above
d. all of the above
A bacterial species has a generation time of 15 minutes and is growing exponentially. If there are 2 cells initially how many cells are there after 90 minutes?
a. 256
b. 128
c. 64
d. 32
e. none of the above
b. 128
2*2^6=128
Which of the following statements are true about bacteria that are photoautotrophs?
a. They derive energy from chemical compounds and obtain carbon from organic compounds
b. They can fix carbon dioxide using electrons derived from the oxidation of an inorganic compound
c. They can fix carbon dioxide using energy derived from light
d. All of the above
e. None of the above
c. they can fix carbon dioxide using energy derived from light
Most bacterial cells reproduce by
a. the budding of daughter cells from a mother cell
b. forming spores that later germinate
c. binary fission
d. production of gametes and sexual reproduction
c. binary fission
Which of these are routinely used to obtain a pure culture of bacteria?
a. swan necked flasks
b. agar streak plates
c. dilution plates
d. microscopes
b. agar streak plates
Which of the following statements is true with respect to heterotrophic organisms?
a. They have the ability to use either preformed organic compounds as sources of carbon or they can fix carbon dioxide from the atmosphere during photosynthesis
b. The invariably ferment carbon-containing substrates
c. The use preformed organic compounds as sources of carbon
d. They prefer bacterial cells of the opposite sex during the process of reproduction
a. They have the ability to use either preformed organic compounds as sources of carbon or they can fix carbon dioxide from the atmosphere during photosynthesis
?
In aerobically respiring prokaryotic organisms the tricarboxylic acid (TCA) cycle:
a. provides cells with ATP that is required for cell growth
b. provides cells with important anabolic intermediates that are required for growth
c. provides a means to completely oxidize organic substrates
d. answers (a) and (b) are both correct
e. answers (a), (b) and (c) are all correct
e. answers (a), (b), and (c) are all correct
?
The cells of all species of Bacteria and Archaea are very small, and:
a. must be stained before they can be seen using light microscopy
b. can only be seen using electron microscopy
c. can only be seen if they are first Gram stained
d. none of the above
c. can only be seen if they are first Gram stained
?
Prokaryotes evolved early on in the history of the Earth:
a. so their physiology has little in common with Eukaryotes
b. so many aspects of their physiology also occur in Eukaryotes, which evolved much later in in the history of the Earth
c. and Eukaryotes evolved independently at a much later time in the history of the Earth
d. at about the same time that Eukaryotes first appeared on Earth
a. so their physiology has little in common with Eukaryotes
?
In microbial metabolism:
a. substrates are first completely oxidized and only afterwards are the products used for cell growth in anabolic processes
b. some of the intermediates of catabolism are used for anabolism
c. catabolism and anabolism are tightly coordinated processes that occur simultaneously
d. answers (a) and (c) are both correct
e. answers (b) and (c) are both correct
a. substrates are first completely oxidized and only afterwards are the products used for cell growth in anabolic processes
?
Aerobic and anaerobic respiration:
a. are similar in so far as the electrons obtained from the oxidation of substrates are used to reduce an inorganic terminal electron acceptor
b. are similar in so far as the electrons obtained from the oxidation of substrates are used to reduce an organic terminal electron acceptor
c. are similar in so far as the electrons obtained from the oxidation of substrates enter into membrane-bound electron transport chains that cause a H+ gradient to be formed
d. answers (a) and (b) are both correct
e. answers (a) and (c) are both correct
c. are similar in so far as the electrons obtained from the oxidation of substrates enter into membrane-bound electron transport chains that cause a H+ gradient to be formed
?
Bacterial cells reproduce by binary fission, which results in exponential growth of the population. If the size of a bacterial population at time zero (t0) is 20 cells and the generation time is 30 minutes, how many cells will be in the population after 3 hours of growth?
a. It is not possible to calculate the number with the information provided
b. 1280 cells
c. 2560 cells
d. 5120 cells
e. 64 million cells
b. 1280 cells
The most widely used solidifying agent used in bacteriological growth media is:
a. gelatin
b. xanthan gum
c. agar
d. epoxy resin
c. agar
Lipopolysaccharides (LPS) are found in:
a. Gram-positive bacteria
b. Gram-negative bacteria
c. all Bacteria
d. Archaea
e. Eukaryotes
b. gram-negative bacteria
Spontaneous generation is
a. the uncontrolled growth of microorganisms
b. the creation of families of organisms
c. the creation of living organisms from non-living material
d. explains why meat can spoil
c. the creation of living organisms from non-living material
Pasteurization requires
a. vaccinating animals to protect them against Mycobacterium tuberculosis
b. the use of heat to kill most of the microorganisms found in liquids such as milk to
preserve their taste
c. use of closed containers to prevent the spoilage of food
d. the use of heat to kill most of the microorganisms found in liquids to protect against
infectious diseases such as tuberculosis
d. the use of heat to kill most of the microorganisms found in liquids to protect against infectious diseases such as tuberculosis
Koch’s postulates
a. must be followed to prevent infectious disease
b. are steps that must be followed to determine the cause of an infectious disease
c. provide guidelines to prevent acids from being produced during wine making
d. were used by Robert Koch in developing vaccines
b. are steps that must be followed to determine the cause of an infectious disease
Louis Jablot showed
a. if a hay infusion were heated, and the vessel was covered with parchment, then
microorganisms never grew in the hay infusion
b. if a hay infusion was not heated, then microorganisms grew in the hay infusion even
if the vessel was covered with parchment
c. so long as a hay infusion was heated, then microorganisms never grew in the infusion
even if it was exposed to air
d. answers (a) and (b) are correct
e. answers (a) and (c) are correct
d. answers (a) and (b) are correct
Catabolism is
a. the biosynthesis of macromolecules found within cells
b. the sum of metabolism and anabolism
c. the decomposition of organic compounds during metabolism
d. yields energy that is used for cell growth
e. answers (c) and (d) are both correct
e. answers (c) and (d) are both correct
Proteins are
a. Polymers of amino acids that are connected by peptide bonds
b. Are involved in the catalysis of biochemical reactions
c. Have so called “side groups” that affect how amino acids interact
d. Answers (a) and (b) are both correct
e. Answers (a), (b), and (c) are all correct
e. answers (a), (b), and (c) are all correct
The algal blooms that occur in Lake Erie and other bodies of water are primarily caused by
a. Global warming
b. Fertilizer run off from agricultural fields and residential areas
c. Industrial pollution
d. The extinction of aquatic species
e. None of the above
b. fertilizer runoff from agricultural fields and residential areas
Which of the following statements about phospholipids is true?
a. are composed molecules that are entirely hydrophilic
b. are composed molecules that are entirely hydrophobic
c. are the principle components of cell membranes
d. have “heads” and “tails” that both have phosphate groups
c. are the principle components of cell membranes
A molecule that undergoes reduction
a. becomes phosphorylated
b. loses a hydrogen atom
c. gains one or more electrons
d. loses one or more electrons
c. gains one or more electrons
The energy from catabolic reactions is used to produce
a. ADP
b. ATP
c. AMP
d. phosphate
b. ATP
During metabolism
a. catabolism and anabolism both occur
b. energy from catabolism is conserved as ATP and used in anabolism to make the
macromolecules found in cells
c. energy from catabolism is conserved as ATP and used in anabolism where it is used
to break down substrate molecules
d. answers (a) and (b) are both correct
b. energy from catabolism is conserved as ATP and used in anabolism to make the macromolecules found in cells
During glycolysis
a. glucose is metabolized to produce pyruvate
b. substrate level phosphorylation results in the formation of 4 ATP
c. the substrate is oxidized
d. answers (a) and (b) are both correct
e. answers (a), (b) and (c) are all correct
e. answers (a), (b), and (c) are all correct
During fermentation
a. NADH is oxidized to form NAD+
b. the terminal electron acceptor is an organic compound
c. ATP is formed from ADP and Pi
d. answers (a) and (b) are both correct
e. answers (a), (b) and (c) are all correct
e. answers (a), (b), and (c) are all correct
Central metabolism
a. is important for the formation of anabolic intermediates
b. is important for ‘capturing’ energy during the catabolism of a substrate
c. is used for the catabolism many different substrates
d. answers (b) and (c) are both correct
e. answers (a), (b) and (c) are all correct
c. is used for the catabolism many different substrates
What is the fate of pyruvic acid in an organism that uses aerobic respiration?
a. it is reduced to lactic acid
b. it is oxidized in the TCA cycle
c. it is catabolized in glycolysis
d. it is completely reduced to produce carbon dioxide
d. it is completely reduced to produce carbon dioxide
In fermentation,
a. the final electron acceptor is an organic compound
b. a large amount of ATP is produced
c. oxygen is required
d. an electron transport chain is required
a. the final acceptor is an organic compound
In anaerobic respiration, the final electron acceptor is
a. oxygen
b. ATP
c. an inorganic molecule other than oxygen
d. an organic molecule
c. an inorganic molecule other than oxygen
What are the overall (net) products of glycolysis?
a. 1 pyruvic acid, 4 ATP, 2 NADH
b. 1 pyruvic acid, 2 ATP, 4 NADH
c. 2 pyruvic acid, 4 ATP, 2 NADH
d. 2 pyruvic acid, 2 ATP, 2 NADH
d. 2 pyretic acid, 2 ATP, and 2 NADH
The energy from catabolic reactions is used to produce
a. ADP
b. AMP
c. ATP
d. phosphate
c. ATP
Electron transport chains are a part of what process?
a. glycolysis
b. oxidative phosphorylation
c. substrate transport
d. substrate-level phosphorylation
b. oxidative phosphorylation
During respiration protons (H+) received from NADH
a. act as coenzyme
b. are passed along the electron transport chain along with the electrons
c. are the terminal electron acceptors
d. are pumped across the cell membrane to the outside of the cell
d. are pumped across the call membrane to the outside of the cell
During aerobic respiration oxygen acts as
a. is combined with electrons and passed along an electron transport chain
b. a reducing agent
c. the terminal electron acceptor
d. a coenzyme
c. terminal electron acceptor
When protons are pumped outside the cell membrane
a. water is made
b. a proton motive force is created that drives ATP synthesis
c. NADH gets reduced
d. electrons are lost
b. a proton motive force is created that drives ATP synthesis
________ use electrons from reduced inorganic compounds as a source of energy and CO2 as a source of carbon.
a. photoautotrophs
b. photoheterotrophs
c. chemoautotrophs
d. chemoheterotrophs
c. chemoautotrophs
The generation time of a particular bacterial species is 30 minutes. Starting with one cell, how many are there after 4 hours?
a. 4
b. 8
c. 256
d. none of the above
c. 256
1*2^8=256
Generation time can best be defined as
a. the length of time it takes for lag phase
b. the duration of log phase
c. the time it takes for a cell to divide
d. how many generations a cell can divide
c. the time it takes for the cells to divide
Bacterial growth is usually graphed using ________ scales.
a. arithmetic
b. exponential
c. semi-logarithmic
d. inverse
c. semi-logarithmic
Most bacteria reproduce by
a. aerial hyphae
b. fragmentation
c. mitosis
d. binary fission
e. budding
d. binary fission
