MIBO 3500L exam 2 UPDATED ACTUAL Questions And Correct Answers
C
Terms in this set (79)
Define 'Extremophiles' microbes that grow at harsh conditions
thermophile optimum temperature between 45C and 70C
Hyperthermophile 70C or greater
Mesophile 25-45 C - human body is 37 C
Psychotrophs 15-30 C
Psychrophiles -5 to 15 C
Neutrophiles organisms that thrive in neutral (pH 7) environments
Acidophiles thrive at pH below 5.5
Alkaliphiles organisms that live above pH 8.5
Halotolerant organisms survive up to 10% solute concentration
Halophiles "salt-loving" archaea that live in environments that have very high salt
concentrations
marine bacteria - need 3% NaCl
Aerobic requires oxygen to grow
Aerotolerant do not utilize oxygen but can survive and grow in its presence
Microaerophile require small amounts of oxygen to grow
Facultative anaerobes use oxygen to grow but can grow without it as well
Anaerobes cannot grow in the presence of oxygen
experimental designs that can be used to distinguish the different temps
cardinal terms for unknown organisms different pH environments
differing salt concentrations
Aerotolerance: candle jar for microaerobic, gaspak for anaerobic, basic agar for
aerobic
Why do we want to control the growth of bacteria? they can cause damage to food crops and livestock and cause infection
, bacteriocidal agent that kills bacteria
bacteriostatic inhibits bacterial growth without killing it
Name three methods of physical control Autoclave
incineration
shortwave UV light
How do each of these three examples differ from each UV kills cell through DNA damage, incineration only used on metal, autoclave
other? denatures cellular properties
How can we test if these physical methods of control are check for bacterial growth
working properly?
What is the difference between a 'disinfectant' and an disinfectants are used on inanimate objects
'antiseptic'? Antiseptics are use on skin or living tissue
When using chemical methods of control how might the TSAYE mediums are limited and unlikely to change activity of the disinfectants
composition of the agar plate affect the effectiveness of blood agar medium can interact with chemicals in a way that impacts their ability
the control measure? to control bacterial growth
How does a 'disk diffusion assay' work, what are disks are impregnated with a test compound and laid on prepared lawn of
indications that a compound is effective or not at control bacteria -> incubated for 24-48 hr to allow growth
bacterial growth? chemicals that control growth will create a radical zone of inhibition if compound
is effective
Define 'zone of inhibition' where concentration of chemical is too high for the cells to grow
Is the disk diffusion assay a quantitative assay? no, disk diffusion is qualitative because toxicity can't be compared since inhibition
zones are dictated by diffusion properties of the compound, which may vary
How does the size of the ZOI in a disk diffusion assay small ZOI suggests low toxicity or that the chemical doesn't diffuse well
relate to the strength of the control compound?
Describe diffusion in the context of this assay if a chemical is good at diffusing, it will have a larger radius
C
Terms in this set (79)
Define 'Extremophiles' microbes that grow at harsh conditions
thermophile optimum temperature between 45C and 70C
Hyperthermophile 70C or greater
Mesophile 25-45 C - human body is 37 C
Psychotrophs 15-30 C
Psychrophiles -5 to 15 C
Neutrophiles organisms that thrive in neutral (pH 7) environments
Acidophiles thrive at pH below 5.5
Alkaliphiles organisms that live above pH 8.5
Halotolerant organisms survive up to 10% solute concentration
Halophiles "salt-loving" archaea that live in environments that have very high salt
concentrations
marine bacteria - need 3% NaCl
Aerobic requires oxygen to grow
Aerotolerant do not utilize oxygen but can survive and grow in its presence
Microaerophile require small amounts of oxygen to grow
Facultative anaerobes use oxygen to grow but can grow without it as well
Anaerobes cannot grow in the presence of oxygen
experimental designs that can be used to distinguish the different temps
cardinal terms for unknown organisms different pH environments
differing salt concentrations
Aerotolerance: candle jar for microaerobic, gaspak for anaerobic, basic agar for
aerobic
Why do we want to control the growth of bacteria? they can cause damage to food crops and livestock and cause infection
, bacteriocidal agent that kills bacteria
bacteriostatic inhibits bacterial growth without killing it
Name three methods of physical control Autoclave
incineration
shortwave UV light
How do each of these three examples differ from each UV kills cell through DNA damage, incineration only used on metal, autoclave
other? denatures cellular properties
How can we test if these physical methods of control are check for bacterial growth
working properly?
What is the difference between a 'disinfectant' and an disinfectants are used on inanimate objects
'antiseptic'? Antiseptics are use on skin or living tissue
When using chemical methods of control how might the TSAYE mediums are limited and unlikely to change activity of the disinfectants
composition of the agar plate affect the effectiveness of blood agar medium can interact with chemicals in a way that impacts their ability
the control measure? to control bacterial growth
How does a 'disk diffusion assay' work, what are disks are impregnated with a test compound and laid on prepared lawn of
indications that a compound is effective or not at control bacteria -> incubated for 24-48 hr to allow growth
bacterial growth? chemicals that control growth will create a radical zone of inhibition if compound
is effective
Define 'zone of inhibition' where concentration of chemical is too high for the cells to grow
Is the disk diffusion assay a quantitative assay? no, disk diffusion is qualitative because toxicity can't be compared since inhibition
zones are dictated by diffusion properties of the compound, which may vary
How does the size of the ZOI in a disk diffusion assay small ZOI suggests low toxicity or that the chemical doesn't diffuse well
relate to the strength of the control compound?
Describe diffusion in the context of this assay if a chemical is good at diffusing, it will have a larger radius
