MGY277 5-8 Exam Study Set
Define:
1. Psychrophile
2. Psychrotroph
3. Mesophile
4. Thermophile
5. Hyperthermophile
6. Neutrophile
7. Acidophile
8. Alkalophile
9. Halophile
10. Halotolerant bacteria - Answer 1. Psychrophile: -5-15C
2. Psychrotroph: 20-30C
3. Mesophile: 25-45C
4. Thermophile: 45-70C
5. Hyperthermophile: 70-110C
6. Neutrophile: pH 5-8, near 7
7. Acidophile: pH below 5.5
8. Alkalophile: pH above 8.5
9. Halophile: REQUIRE high-salt concentrations (3% - 9% salt)
10. Halotolerant bacteria: endure up to 10% salt
what are the differences between:
1. facultative anaerobes
2. obligate aerobes
3. obligate anaerobes
4. microaerophiles
, 5. aerotolerant anaerobes - Answer 1. facultative anaerobes: grows best when O2
present, can grow without it
2. obligate aerobes: must have O2
3. obligate anaerobes: must NOT have O2
4. microaerophiles: need small amounts of O2; large amount is inhibitory
5. aerotolerant anaerobes: indifferent
what is catalase? what is superoxide dismutase? - Answer Catalase:
converts H2O2 -> O2 + H2O
almost all bacteria produce it (expect for aerotolerant anaerobes)
Superoxide dismutase:
almost all organisms that grow in oxygen produce it
inactivates superoxide by converting it to O2 and H2O2
Describe the principles of:
1. sterilization
2. disinfection
3. pasteurization
4. decontamination
5. sanitization
6. preservation - Answer 1. sterilization: remove all microbes so they can't multiply or
revive (not including prions)
2. disinfection: eliminate all pathogens, some microbes may remain (disinfectant for
inanimate objects, antiseptics for living tissues)
3. pasteurization: heating to reduce number of spoilage organisms
4. decontamination: reduce pathogen to level of safety
5. sanitization: reduce microbial population to accepted health standards
6. preservation: delay spoilage of food (slow microbial growth)
what important factors need to be considered when selecting a germicidal chemical? -
Answer 1. toxicity
2. activity in presence of organic material
Define:
1. Psychrophile
2. Psychrotroph
3. Mesophile
4. Thermophile
5. Hyperthermophile
6. Neutrophile
7. Acidophile
8. Alkalophile
9. Halophile
10. Halotolerant bacteria - Answer 1. Psychrophile: -5-15C
2. Psychrotroph: 20-30C
3. Mesophile: 25-45C
4. Thermophile: 45-70C
5. Hyperthermophile: 70-110C
6. Neutrophile: pH 5-8, near 7
7. Acidophile: pH below 5.5
8. Alkalophile: pH above 8.5
9. Halophile: REQUIRE high-salt concentrations (3% - 9% salt)
10. Halotolerant bacteria: endure up to 10% salt
what are the differences between:
1. facultative anaerobes
2. obligate aerobes
3. obligate anaerobes
4. microaerophiles
, 5. aerotolerant anaerobes - Answer 1. facultative anaerobes: grows best when O2
present, can grow without it
2. obligate aerobes: must have O2
3. obligate anaerobes: must NOT have O2
4. microaerophiles: need small amounts of O2; large amount is inhibitory
5. aerotolerant anaerobes: indifferent
what is catalase? what is superoxide dismutase? - Answer Catalase:
converts H2O2 -> O2 + H2O
almost all bacteria produce it (expect for aerotolerant anaerobes)
Superoxide dismutase:
almost all organisms that grow in oxygen produce it
inactivates superoxide by converting it to O2 and H2O2
Describe the principles of:
1. sterilization
2. disinfection
3. pasteurization
4. decontamination
5. sanitization
6. preservation - Answer 1. sterilization: remove all microbes so they can't multiply or
revive (not including prions)
2. disinfection: eliminate all pathogens, some microbes may remain (disinfectant for
inanimate objects, antiseptics for living tissues)
3. pasteurization: heating to reduce number of spoilage organisms
4. decontamination: reduce pathogen to level of safety
5. sanitization: reduce microbial population to accepted health standards
6. preservation: delay spoilage of food (slow microbial growth)
what important factors need to be considered when selecting a germicidal chemical? -
Answer 1. toxicity
2. activity in presence of organic material
