BIOL 3201 Lab 5 Study Guide Exam with
Detailed Answers 2026/2027.
What range of temperature can microorganisms grow in? - Answer 0-100°C
What are the four categories that microorganisms are split into? - Answer Psychrophiles,
mesophiles, thermophiles, and hyperthermophiles
Psychrophile optimal temperature - Answer -5-20°C
Where are psychrophiles found? - Answer In icy waters of the Arctic and Antarctic
Mesophile optimal temperature - Answer 20-50°C
What category do most microbes fall into? - Answer Mesophiles
Thermophile optimal temperature - Answer 50-80°C
Where are most thermophiles found? - Answer In soils where midday temperature can reach
greater than 50°C or in compost piles where temperatures exceed 60-65°C
Hyperthermophile optimal temperature - Answer 80° and above
Where are hyperthermophiles typically found? - Answer In isolate thermal vents deep within
the ocean floor and from volcanic heated hot springs
Psychrotophs - Answer Bacteria that are able to grow higher or lower than their temperature
optima
What is greatly affected by temperature? - Answer Enzymes, cell membranes and transport,
and ribosomes.
What occurs at optimal temperature? - Answer Maximal enzyme activity
What occurs above the optimal temperature? - Answer Enzymes denature and activity loss.
, Membrane lipids can be destroyed, resulting in serious damage to the membrane and death of
the organism.
Ribosomes cease to function adequately.
What occurs below the optimal temperature? - Answer Chemical activity slows down.
The transport of nutrients in to the cell also decreases due to fluidity changes in the membranes
What two physiological reactions will the environmental effects experiment measure? - Answer
Pigment production and growth rate
Serratia marcescens produces? - Answer Prodigiosin
What color pigment is prodigiosin? - Answer Red pigment
Prodigiosin - Answer An antibiotic that has been tested in clinical trials for the treatment of
pancreatic cancer.
What percent does oxygen make up in the atmosphere? - Answer 21%
Obligate (strict) aerobes - Answer Bacteria that MUST grow in oxygen because their
metabolism requires oxygen
What do obligate aerobes carry out? - Answer Respiration and use oxygen as the terminal
electron acceptor.
What are examples of obligate (strict) aerobes? - Answer Pseudomonas, Micrococcus, and
many Bacillus
Microaerophiles - Answer Aerobic bacteria that prefer 2-10% oxygen rather than the 21%
found in the atmosphere. Lower oxygen concentration is necessary.
Do microaerophiles carry out respiratory metabolism (respiration)? - Answer Yes, in lower
oxygen concentration
What are examples of microaerophiles? - Answer Helicobacter pylori and Campylobacter
Facultative anaerobes - Answer Bacteria that grow well in aerobic conditions, but can also
grow anaerobically when oxygen is not available
Detailed Answers 2026/2027.
What range of temperature can microorganisms grow in? - Answer 0-100°C
What are the four categories that microorganisms are split into? - Answer Psychrophiles,
mesophiles, thermophiles, and hyperthermophiles
Psychrophile optimal temperature - Answer -5-20°C
Where are psychrophiles found? - Answer In icy waters of the Arctic and Antarctic
Mesophile optimal temperature - Answer 20-50°C
What category do most microbes fall into? - Answer Mesophiles
Thermophile optimal temperature - Answer 50-80°C
Where are most thermophiles found? - Answer In soils where midday temperature can reach
greater than 50°C or in compost piles where temperatures exceed 60-65°C
Hyperthermophile optimal temperature - Answer 80° and above
Where are hyperthermophiles typically found? - Answer In isolate thermal vents deep within
the ocean floor and from volcanic heated hot springs
Psychrotophs - Answer Bacteria that are able to grow higher or lower than their temperature
optima
What is greatly affected by temperature? - Answer Enzymes, cell membranes and transport,
and ribosomes.
What occurs at optimal temperature? - Answer Maximal enzyme activity
What occurs above the optimal temperature? - Answer Enzymes denature and activity loss.
, Membrane lipids can be destroyed, resulting in serious damage to the membrane and death of
the organism.
Ribosomes cease to function adequately.
What occurs below the optimal temperature? - Answer Chemical activity slows down.
The transport of nutrients in to the cell also decreases due to fluidity changes in the membranes
What two physiological reactions will the environmental effects experiment measure? - Answer
Pigment production and growth rate
Serratia marcescens produces? - Answer Prodigiosin
What color pigment is prodigiosin? - Answer Red pigment
Prodigiosin - Answer An antibiotic that has been tested in clinical trials for the treatment of
pancreatic cancer.
What percent does oxygen make up in the atmosphere? - Answer 21%
Obligate (strict) aerobes - Answer Bacteria that MUST grow in oxygen because their
metabolism requires oxygen
What do obligate aerobes carry out? - Answer Respiration and use oxygen as the terminal
electron acceptor.
What are examples of obligate (strict) aerobes? - Answer Pseudomonas, Micrococcus, and
many Bacillus
Microaerophiles - Answer Aerobic bacteria that prefer 2-10% oxygen rather than the 21%
found in the atmosphere. Lower oxygen concentration is necessary.
Do microaerophiles carry out respiratory metabolism (respiration)? - Answer Yes, in lower
oxygen concentration
What are examples of microaerophiles? - Answer Helicobacter pylori and Campylobacter
Facultative anaerobes - Answer Bacteria that grow well in aerobic conditions, but can also
grow anaerobically when oxygen is not available
