SOD THEORY 2 COMPREHENSIVE EXAM
STUDY GUIDE COMPLETE QUESTIONS AND
SOLUTIONS
●● What are the oxygen classifications of microbes?
Answer: Obligate aerobes, facultative anaerobes, aerotolerant anaerobes,
obligate anaerobes, and microaerophiles.
●● Psychrophile
Answer: Grows best at 0-20°C (cold-loving).
●● Psychrotroph
Answer: Can grow at refrigerator temperatures but grows best at 20-
30°C.
●● Mesophile
Answer: Grows best at 20-45°C; most human pathogens.
●● Thermophile
Answer: Grows best at 45-80°C
●● Hyperthermophile
,Answer: Grows best above 80°C.
●● Psychrotolerant
Answer: Can survive or tolerate cold temperatures, but does not
necessarily grow best in the cold.
●● What environmental factors affect microbial growth?
Answer: Temperature, oxygen, pH, osmotic pressure, moisture, and
nutrient availability.
●● How can environmental factors be used to limit microbial growth?
Answer: By creating conditions outside the microbe's preferred range,
slowing growth or causing death.
●● How does heat kill bacteria?
Answer: Heat denatures proteins and damages cell membranes.
●● How does cold affect bacteria?
Answer: Slows metabolism and enzyme activity.
●● Obligate aerobe
Answer: Requires oxygen; uses aerobic respiration.
, ●● Facultative anaerobe
Answer: Can grow with or without oxygen; prefers aerobic respiration.
●● Aerotolerant anaerobe
Answer: Does not use oxygen but tolerates it; uses fermentation.
●● Obligate anaerobe
Answer: Cannot survive in oxygen.
●● What is superoxide dismutase (SOD)?
Answer: An enzyme that detoxifies toxic oxygen radicals.
●● Who has SOD?
Answer: Obligate aerobes, facultative anaerobes, aerotolerant anaerobes,
most microaerophiles.
●● Who lacks SOD?
Answer: Obligate anaerobes.
●● osmotic lysis
Answer: Cell bursts because water enters in a hypotonic environment
STUDY GUIDE COMPLETE QUESTIONS AND
SOLUTIONS
●● What are the oxygen classifications of microbes?
Answer: Obligate aerobes, facultative anaerobes, aerotolerant anaerobes,
obligate anaerobes, and microaerophiles.
●● Psychrophile
Answer: Grows best at 0-20°C (cold-loving).
●● Psychrotroph
Answer: Can grow at refrigerator temperatures but grows best at 20-
30°C.
●● Mesophile
Answer: Grows best at 20-45°C; most human pathogens.
●● Thermophile
Answer: Grows best at 45-80°C
●● Hyperthermophile
,Answer: Grows best above 80°C.
●● Psychrotolerant
Answer: Can survive or tolerate cold temperatures, but does not
necessarily grow best in the cold.
●● What environmental factors affect microbial growth?
Answer: Temperature, oxygen, pH, osmotic pressure, moisture, and
nutrient availability.
●● How can environmental factors be used to limit microbial growth?
Answer: By creating conditions outside the microbe's preferred range,
slowing growth or causing death.
●● How does heat kill bacteria?
Answer: Heat denatures proteins and damages cell membranes.
●● How does cold affect bacteria?
Answer: Slows metabolism and enzyme activity.
●● Obligate aerobe
Answer: Requires oxygen; uses aerobic respiration.
, ●● Facultative anaerobe
Answer: Can grow with or without oxygen; prefers aerobic respiration.
●● Aerotolerant anaerobe
Answer: Does not use oxygen but tolerates it; uses fermentation.
●● Obligate anaerobe
Answer: Cannot survive in oxygen.
●● What is superoxide dismutase (SOD)?
Answer: An enzyme that detoxifies toxic oxygen radicals.
●● Who has SOD?
Answer: Obligate aerobes, facultative anaerobes, aerotolerant anaerobes,
most microaerophiles.
●● Who lacks SOD?
Answer: Obligate anaerobes.
●● osmotic lysis
Answer: Cell bursts because water enters in a hypotonic environment
