MIC 205 EXAM 2 DAYDIF QUESTIONS & ANSWERS
Microbial growth is an increase in (cell number/size)? - Answers -CELL NUMBER
discrete colony - Answers -aggregation of cells arising from a single parent cell
visible on surface of solid media
solid media - all same DNA, replicas of e/o
dispersed cells - Answers -single cells suspended in liquid media
don't cluster together, they are free to spread out
complex biofilm - Answers -collection of microbes living on a surface in a complex
community
most common form in nature
3 things all cells need for metabolism? - Answers -source of carbon
source of energy
source of electrons or hydrogen atoms
autotrophs - Answers -use CO2 (an inorganic source of carbon) as carbon source, they
feed themselves
heterotrophs - Answers -break down organic molecules (proteins, CHO, nucleic acids,
lipids) from other organisms as a food source
chemotrophs - Answers -obtain energy from chemicals in redox reactions (aerobic
respiration, anaerobic respiration, fermentation)
phototrophs - Answers -obtain energy from light
microbial doubling time - Answers -replicate their chromosomes in 30 mins
arithmetic growth - Answers -population increases by the same amount over each time
interval
logarithmic growth - Answers -1 becomes 2, 2 becomes 4, 4 become 8, 8 becomes 16,
16 becomes 32, etc.
bacterial cells grow this way
,Increase to millions in a few hours
clinical specimens - Answers -human materials (feces, saliva, cerebrospinal fluid, or
blood) examined or tested for presence of bacteria and other microbes
clinical sampling considerations - Answers -proper specimen
technique
timely delivery
proper culture methods
(proper specimen collection + timely delivery to the clinical lab are physicians
responsibility)
Majority of microorganisms (have/never have) been grown in any culture media? -
Answers -NEVER HAVE
defined (synthetic) media - Answers -know exactly the concentration of every chemical
in the media, everything can be found on chemistry shelf
specifically putting exactly 1g of this, know the exact pH, know exactly everything about
it
complex media - Answers -rich source of nutrients like a beef broth type of media, but
on day to day basis, different amount of amino acid present in media
very variable - ex: each scoop contains diff amounts of nutrients
selective media - Answers -suppress growth of unwanted bacteria and encourage
growth of desired microbes
adding something to kill a bunch of microbes off, and wanting to grow a selective media
example: dextrose agar plate has pH of 4-5 it is selective bc bacteria won't grow at that
pH, selecting for mold or fungus to grow on that plate
differential media - Answers -does not inhibit any microbes from growing, allows growth
of several types of microbes and displays visible differences among those microbes
oxidizing red blood cells and changing color
anaerobic media - Answers -encourages anaerobic bacteria to grow
, transport media - Answers -used to maintain and preserve specimens that have to be
held for a period of time before clinical analysis
example: important for 3rd world country, take samples from people in far away place,
put them in this media to bring it back to your lab
lag phase of bacterial growth - Answers -no growth
enzymatic activity going on, sensing what is in the environment and adapting to local
conditions
log (exponential) phase of bacterial growth - Answers -high growth + lots of enzymatic
reactions happening
the population is most actively growing
stationary phase of bacterial growth - Answers -all cellular structures built at this point
reached a saturation point
plateau's in growth - equal growth to equal death, no increase in population
microorganisms stop growing bc of lack of nutrients, waste products build up (acids),
environmental changes, etc.
death phase of microbial growth - Answers -due to environment pollution and limited
resources, entire population rapidly declines
the organisms are dying more quickly than they can be replaced by new organisms
first generations of bacteria will die before last but at the same rate
what phase of growth will microorganism be most sensitive to antimicrobials? -
Answers -LOG phase
penicillin inhibits cell wall. growing in log phase means they're increasing in cellular #
which means they are making their peptidoglycan. most drugs affect cells in log phase -
specifically cell wall inhibitors + protein synthesis inhibitors
microbes are classified based on their _____ and _____ requirements? - Answers -
nutritional + physical requirements
T/F: neither gaseous oxygen (O2) nor oxygen covalently bound in compounds is
poisonous - Answers -TRUE
aerobes - Answers -require oxygen to grow
Microbial growth is an increase in (cell number/size)? - Answers -CELL NUMBER
discrete colony - Answers -aggregation of cells arising from a single parent cell
visible on surface of solid media
solid media - all same DNA, replicas of e/o
dispersed cells - Answers -single cells suspended in liquid media
don't cluster together, they are free to spread out
complex biofilm - Answers -collection of microbes living on a surface in a complex
community
most common form in nature
3 things all cells need for metabolism? - Answers -source of carbon
source of energy
source of electrons or hydrogen atoms
autotrophs - Answers -use CO2 (an inorganic source of carbon) as carbon source, they
feed themselves
heterotrophs - Answers -break down organic molecules (proteins, CHO, nucleic acids,
lipids) from other organisms as a food source
chemotrophs - Answers -obtain energy from chemicals in redox reactions (aerobic
respiration, anaerobic respiration, fermentation)
phototrophs - Answers -obtain energy from light
microbial doubling time - Answers -replicate their chromosomes in 30 mins
arithmetic growth - Answers -population increases by the same amount over each time
interval
logarithmic growth - Answers -1 becomes 2, 2 becomes 4, 4 become 8, 8 becomes 16,
16 becomes 32, etc.
bacterial cells grow this way
,Increase to millions in a few hours
clinical specimens - Answers -human materials (feces, saliva, cerebrospinal fluid, or
blood) examined or tested for presence of bacteria and other microbes
clinical sampling considerations - Answers -proper specimen
technique
timely delivery
proper culture methods
(proper specimen collection + timely delivery to the clinical lab are physicians
responsibility)
Majority of microorganisms (have/never have) been grown in any culture media? -
Answers -NEVER HAVE
defined (synthetic) media - Answers -know exactly the concentration of every chemical
in the media, everything can be found on chemistry shelf
specifically putting exactly 1g of this, know the exact pH, know exactly everything about
it
complex media - Answers -rich source of nutrients like a beef broth type of media, but
on day to day basis, different amount of amino acid present in media
very variable - ex: each scoop contains diff amounts of nutrients
selective media - Answers -suppress growth of unwanted bacteria and encourage
growth of desired microbes
adding something to kill a bunch of microbes off, and wanting to grow a selective media
example: dextrose agar plate has pH of 4-5 it is selective bc bacteria won't grow at that
pH, selecting for mold or fungus to grow on that plate
differential media - Answers -does not inhibit any microbes from growing, allows growth
of several types of microbes and displays visible differences among those microbes
oxidizing red blood cells and changing color
anaerobic media - Answers -encourages anaerobic bacteria to grow
, transport media - Answers -used to maintain and preserve specimens that have to be
held for a period of time before clinical analysis
example: important for 3rd world country, take samples from people in far away place,
put them in this media to bring it back to your lab
lag phase of bacterial growth - Answers -no growth
enzymatic activity going on, sensing what is in the environment and adapting to local
conditions
log (exponential) phase of bacterial growth - Answers -high growth + lots of enzymatic
reactions happening
the population is most actively growing
stationary phase of bacterial growth - Answers -all cellular structures built at this point
reached a saturation point
plateau's in growth - equal growth to equal death, no increase in population
microorganisms stop growing bc of lack of nutrients, waste products build up (acids),
environmental changes, etc.
death phase of microbial growth - Answers -due to environment pollution and limited
resources, entire population rapidly declines
the organisms are dying more quickly than they can be replaced by new organisms
first generations of bacteria will die before last but at the same rate
what phase of growth will microorganism be most sensitive to antimicrobials? -
Answers -LOG phase
penicillin inhibits cell wall. growing in log phase means they're increasing in cellular #
which means they are making their peptidoglycan. most drugs affect cells in log phase -
specifically cell wall inhibitors + protein synthesis inhibitors
microbes are classified based on their _____ and _____ requirements? - Answers -
nutritional + physical requirements
T/F: neither gaseous oxygen (O2) nor oxygen covalently bound in compounds is
poisonous - Answers -TRUE
aerobes - Answers -require oxygen to grow
