MICROBIOLOGY 2117 CORE MAIN EXAMS SET
QUESTIONS AND ANSWERS SURE A+
✔✔autotrophic - ✔✔self-nourishing; pertaining to the ability of an organism to produce
its own nutrients from inorganic compounds
✔✔fastidious bacteria - ✔✔require growth factors from environment because they
cannot synthesize them; Neisseria
✔✔obligate aerobe - ✔✔An organism that requires oxygen to survive (aerobic
metabolism only).
✔✔obligate anaerobe - ✔✔An organism that only carries out fermentation or anaerobic
respiration. Such organisms cannot use oxygen and in fact may be poisoned by it.
✔✔facultative anaerobe - ✔✔An organism that makes ATP by aerobic respiration if
oxygen is present but that switches to fermentation under anaerobic conditions.
✔✔lyophilization - ✔✔used for very long-term storage; freeze-drying- removing water
from frozen culture using intense vacuum converting ice directly into a gas
✔✔acidophile - ✔✔an organism that grows best at low pH; typically below pH 6
, ✔✔alkalinophile - ✔✔Bacteria that inhabit alkaline soils and water and can continue to
grow at a pH of 11.5
✔✔psychrophile - ✔✔An organism with a growth temperature optimum of 15 degrees
Celsius or lower and a maximum growth temperature below 20 degrees Celsius.
✔✔mesophile - ✔✔bacteria that prefers moderate temperature and develops best at
temperatures between 25 C and 40 C
✔✔thermophile - ✔✔an organism that has adapted to living in very high temperatures
(heat), such as bacteria or algae
✔✔barophile - ✔✔an organism which can only exist at pressures found at great depths
ex: deep sea microbes
✔✔halophile - ✔✔archaea that live in environments with very high salt concentrations
✔✔pure culture - ✔✔culture of a single form of microorganism uncontaminated by other
organisms
✔✔Selective media - ✔✔Contain one or more agents that inhibit growth of some
microbes and encourage growth of the desired microbes
✔✔differential media - ✔✔make it easier to distinguish colonies of the desired organism
from other colonies growing on the same plate. The colonies have different colors or
cause different changes in the surrounding medium. Sometimes selective and
differential functions are combined in the one medium.
✔✔enhancement media - ✔✔supports the growth of many organisms, especially
fastidious ones.
✔✔complex media - ✔✔contain necessary nutrients but the exact make up of the media
is not known. (uses beef broth, extracts, etc)
✔✔If a medium turns green with the growth of one bacteria but brown with another,
what type of medium would that be? - ✔✔differential
✔✔How are anaerobic bacteria grown in the lab? - ✔✔In a Thioglycollate Medium. The
anaerobic bacteria tend to grow at the bottom of the tube and away from the O2.
✔✔How would obligate aerobes and facultative anaerobes show different growth in the
nutrient broth? - ✔✔the obligate aerobes would tend to grow at the top of the tube
where O2 was greatest. Facultative anaerobes would be scattered throughout the tube
but more toward the top.
QUESTIONS AND ANSWERS SURE A+
✔✔autotrophic - ✔✔self-nourishing; pertaining to the ability of an organism to produce
its own nutrients from inorganic compounds
✔✔fastidious bacteria - ✔✔require growth factors from environment because they
cannot synthesize them; Neisseria
✔✔obligate aerobe - ✔✔An organism that requires oxygen to survive (aerobic
metabolism only).
✔✔obligate anaerobe - ✔✔An organism that only carries out fermentation or anaerobic
respiration. Such organisms cannot use oxygen and in fact may be poisoned by it.
✔✔facultative anaerobe - ✔✔An organism that makes ATP by aerobic respiration if
oxygen is present but that switches to fermentation under anaerobic conditions.
✔✔lyophilization - ✔✔used for very long-term storage; freeze-drying- removing water
from frozen culture using intense vacuum converting ice directly into a gas
✔✔acidophile - ✔✔an organism that grows best at low pH; typically below pH 6
, ✔✔alkalinophile - ✔✔Bacteria that inhabit alkaline soils and water and can continue to
grow at a pH of 11.5
✔✔psychrophile - ✔✔An organism with a growth temperature optimum of 15 degrees
Celsius or lower and a maximum growth temperature below 20 degrees Celsius.
✔✔mesophile - ✔✔bacteria that prefers moderate temperature and develops best at
temperatures between 25 C and 40 C
✔✔thermophile - ✔✔an organism that has adapted to living in very high temperatures
(heat), such as bacteria or algae
✔✔barophile - ✔✔an organism which can only exist at pressures found at great depths
ex: deep sea microbes
✔✔halophile - ✔✔archaea that live in environments with very high salt concentrations
✔✔pure culture - ✔✔culture of a single form of microorganism uncontaminated by other
organisms
✔✔Selective media - ✔✔Contain one or more agents that inhibit growth of some
microbes and encourage growth of the desired microbes
✔✔differential media - ✔✔make it easier to distinguish colonies of the desired organism
from other colonies growing on the same plate. The colonies have different colors or
cause different changes in the surrounding medium. Sometimes selective and
differential functions are combined in the one medium.
✔✔enhancement media - ✔✔supports the growth of many organisms, especially
fastidious ones.
✔✔complex media - ✔✔contain necessary nutrients but the exact make up of the media
is not known. (uses beef broth, extracts, etc)
✔✔If a medium turns green with the growth of one bacteria but brown with another,
what type of medium would that be? - ✔✔differential
✔✔How are anaerobic bacteria grown in the lab? - ✔✔In a Thioglycollate Medium. The
anaerobic bacteria tend to grow at the bottom of the tube and away from the O2.
✔✔How would obligate aerobes and facultative anaerobes show different growth in the
nutrient broth? - ✔✔the obligate aerobes would tend to grow at the top of the tube
where O2 was greatest. Facultative anaerobes would be scattered throughout the tube
but more toward the top.
