MICROBIO 4000: Exam 2 Final Test
Questions All Solved Correctly.
Microbial Growth - Answer Increase in the number of cells in a population
Physical Requirements - Answer Requirements include temperature, pH, and osmotic
pressure
Chemical Requirements - Answer Requirements include source of carbon and other elements
Temperature - Answer One of the physical requirements for microbial growth; five different
categories (psychrophiles, psychographs, mesophiles, thermophiles and hyperthermophiles)
Psychrophile - Answer Cold-loving (even frozen) microbes that thrive at temperatures of 10-
15°C
Psychotroph - Answer Microbes that thrive at room temperature (temperatures of around
20-30°C) but can survive as low as 0°C
Mesophile - Answer Microbes that thrive at temperatures that resemble that of the human
body (25-40°C)
Thermophile - Answer Microbes that thrive at very warm temperatures (50-60°C)
Hyperthermophile - Answer Microbes that thrive in very hot (even boiling) environments
(>80°C)
pH - Answer One of the physical requirements for microbial growth; three different
categories (alkaliphiles, neutrophiles, and acidophiles)
Alkaliphile - Answer Microbes that thrive at a pH that exceeds 8
Neutrophile - Answer Microbes that thrive at a pH range of 5.5 - 8
Acidophile - Answer Microbes that thrive at a pH that is less than 5.5
,Extremophile - Answer Microbes that thrive in conditions that would kill most other
organisms; typically Archaea
Acid Tolerant - Answer Microbes that may be neutrophiles, but can survive in environments
that are of a lower pH
Osmotic Pressure - Answer Pressure that must be applied to prevent osmotic movement
across a selectively permeable membrane
Facultative Halophile - Answer Microbes that can tolerate SOME osmotic pressure
Obligate Halophile - Answer Microbes that require high osmotic pressures (such as high
concentrations of NaCl) to thrive
Isotonic - Answer Microbial environment in which the external solute concentration matches
that of the internal solute concentration (so that there is no rush of solute in or out of the cell)
Hypertonic - Answer Microbial environment in which the external solute concentration is
higher than internal solute concentration, leading to an efflux of water, causing plasmolysis
Plasmolysis - Answer Condition when a cell is in a hypertonic environment in which water
within the cell is drawn out of the cell due to osmotic pressure, leading to the shriveling of the
cell that can lead to death
Chemically Defined Media - Answer Media used to grow microbes that is composed of exact
amounts of pure chemicals
Complex Media - Answer Media used to grow microbes that contains some ingredients of
unknown composition and/or concentration
Heterotroph - Answer Organism that obtains energy from the foods it consumes
Autotroph - Answer Organism that is able to form nutritional organic substances from simple
inorganic substances such as carbon dioxide
Nitrogen - Answer Element used for ATP, DNA, RNA, and amino acids; source depends on the
microbe
, Sulfur - Answer Element used for some amino acids, vitamins, and cofactors; source could be
protein material or sulfur-containing compounds such as SO4 or H2S
Phosphorus - Answer Element used for DNA, RNA, and some lipids in the cell membrane;
source is PO4
Trace Elements - Answer Used for enzyme cofactors; required in extremely small amounts,
can even be present in water
Organic Growth Factor - Answer Examples are amino acids, nucleic acids, and vitamins that
cannot be synthesized by the cell itself
Auxotroph - Answer Microbe that is unable to synthesize a specific growth factor and must
get it from the environment
Oxygen - Answer Element that is a requirement for some microbial growth; 5 types of
organisms (in relation to this element) = obligate aerobes, obligate anaerobes, facultative
anaerobes, aerotolerant anaerobes, and microaerophiles
Obligate Aerobe - Answer Microbe that requires oxygen to survive; have SOD and catalase
enzymes
Facultative Anaerobe - Answer Microbe that prefers to have oxygen, but has the option for
microbial growth without it; have SOD and catalase enzymes
Obligate Anaerobe - Answer Microbe that must have a lack of oxygen in order to survive
Aerotolerant Anaerobe - Answer Microbe that doesn't use oxygen, but can tolerate it; have
SOD enzymes
Microaerophile - Answer Microbe that prefers a lower concentration of oxygen, but not
completely absent; have low levels of SOD and Catalase enzymes
Reactive Oxygen Species (ROS) - Answer Chemical species that are produced as byproducts of
aerobic metabolism; damages DNA, proteins, the cell membrane, etc; examples include radical
OH, O2-, and radical O2-
Superoxidase Dismutase (SOD) & Catalase - Answer Enzymes that break down reactive
oxygen species
Questions All Solved Correctly.
Microbial Growth - Answer Increase in the number of cells in a population
Physical Requirements - Answer Requirements include temperature, pH, and osmotic
pressure
Chemical Requirements - Answer Requirements include source of carbon and other elements
Temperature - Answer One of the physical requirements for microbial growth; five different
categories (psychrophiles, psychographs, mesophiles, thermophiles and hyperthermophiles)
Psychrophile - Answer Cold-loving (even frozen) microbes that thrive at temperatures of 10-
15°C
Psychotroph - Answer Microbes that thrive at room temperature (temperatures of around
20-30°C) but can survive as low as 0°C
Mesophile - Answer Microbes that thrive at temperatures that resemble that of the human
body (25-40°C)
Thermophile - Answer Microbes that thrive at very warm temperatures (50-60°C)
Hyperthermophile - Answer Microbes that thrive in very hot (even boiling) environments
(>80°C)
pH - Answer One of the physical requirements for microbial growth; three different
categories (alkaliphiles, neutrophiles, and acidophiles)
Alkaliphile - Answer Microbes that thrive at a pH that exceeds 8
Neutrophile - Answer Microbes that thrive at a pH range of 5.5 - 8
Acidophile - Answer Microbes that thrive at a pH that is less than 5.5
,Extremophile - Answer Microbes that thrive in conditions that would kill most other
organisms; typically Archaea
Acid Tolerant - Answer Microbes that may be neutrophiles, but can survive in environments
that are of a lower pH
Osmotic Pressure - Answer Pressure that must be applied to prevent osmotic movement
across a selectively permeable membrane
Facultative Halophile - Answer Microbes that can tolerate SOME osmotic pressure
Obligate Halophile - Answer Microbes that require high osmotic pressures (such as high
concentrations of NaCl) to thrive
Isotonic - Answer Microbial environment in which the external solute concentration matches
that of the internal solute concentration (so that there is no rush of solute in or out of the cell)
Hypertonic - Answer Microbial environment in which the external solute concentration is
higher than internal solute concentration, leading to an efflux of water, causing plasmolysis
Plasmolysis - Answer Condition when a cell is in a hypertonic environment in which water
within the cell is drawn out of the cell due to osmotic pressure, leading to the shriveling of the
cell that can lead to death
Chemically Defined Media - Answer Media used to grow microbes that is composed of exact
amounts of pure chemicals
Complex Media - Answer Media used to grow microbes that contains some ingredients of
unknown composition and/or concentration
Heterotroph - Answer Organism that obtains energy from the foods it consumes
Autotroph - Answer Organism that is able to form nutritional organic substances from simple
inorganic substances such as carbon dioxide
Nitrogen - Answer Element used for ATP, DNA, RNA, and amino acids; source depends on the
microbe
, Sulfur - Answer Element used for some amino acids, vitamins, and cofactors; source could be
protein material or sulfur-containing compounds such as SO4 or H2S
Phosphorus - Answer Element used for DNA, RNA, and some lipids in the cell membrane;
source is PO4
Trace Elements - Answer Used for enzyme cofactors; required in extremely small amounts,
can even be present in water
Organic Growth Factor - Answer Examples are amino acids, nucleic acids, and vitamins that
cannot be synthesized by the cell itself
Auxotroph - Answer Microbe that is unable to synthesize a specific growth factor and must
get it from the environment
Oxygen - Answer Element that is a requirement for some microbial growth; 5 types of
organisms (in relation to this element) = obligate aerobes, obligate anaerobes, facultative
anaerobes, aerotolerant anaerobes, and microaerophiles
Obligate Aerobe - Answer Microbe that requires oxygen to survive; have SOD and catalase
enzymes
Facultative Anaerobe - Answer Microbe that prefers to have oxygen, but has the option for
microbial growth without it; have SOD and catalase enzymes
Obligate Anaerobe - Answer Microbe that must have a lack of oxygen in order to survive
Aerotolerant Anaerobe - Answer Microbe that doesn't use oxygen, but can tolerate it; have
SOD enzymes
Microaerophile - Answer Microbe that prefers a lower concentration of oxygen, but not
completely absent; have low levels of SOD and Catalase enzymes
Reactive Oxygen Species (ROS) - Answer Chemical species that are produced as byproducts of
aerobic metabolism; damages DNA, proteins, the cell membrane, etc; examples include radical
OH, O2-, and radical O2-
Superoxidase Dismutase (SOD) & Catalase - Answer Enzymes that break down reactive
oxygen species
