Openstax Microbiology - Chapter 9 Questions with Verified Solutions Latest Version 2025 Already
Passed
Differential Media - Answers make it easy to distinguish colonies of different microbes by changing the
color of the colony or the color of the medium.
Enrichment Media - Answers encourages growth of desired microbe that represent a fraction of the
organisms present in an inoculation.
Selective Media - Answers Inhibit growth of unwanted organisms and support thee growth of organisms
of interest.
Halotolerant - Answers Do not need a high concentration of salt to grow, but can still survive and divide
in the presence of salt.
Halophiles - Answers require high salt concentration for growth.
Thermophiles - Answers Optimal temep 50c
important for biotechnology
Listeria monocytogens - Answers Grows in refrigerators on/ in
-soft cheese
-deli meat
-hummus
-ice cream
Does not harm humans but can cross the placenta of a pregnant woman and kill the fetus.
Psychophile
Psychophiles - Answers Cold loving, optimal temp at 15c
Mesophiles - Answers Middle Loving, Optimal temp 20-45c
Most human pathogens.
, Normal microbiota
Helicbactor pylori - Answers neutrophile, survives in the stomach because it creates a micro
environment where the pH is nearly neutral.
Does it by urease with breaks down euro two form NH4+ and CO2
Alkaliphiles - Answers grow optimally at pH above 8.5
Acidophiles - Answers grow optimally at a pH of 5.5 or less.
Ex: Lactobacillus, contributes to the pH of the vagina of 4.0
Neutrophiles - Answers grow optimally at a pH one or two units within the neutral pH range.
Ex: E. coli
Most sensitive to pH change - Answers Proteins. Modifies the ionization of amino acid functional groups
and disrupts the hydrogen bonding.
causes the cell to flood.
Catalase and hydrogen peroxide reaction - Answers 2H2O2 -> 2H2O + O2
Catalase - Answers tested in the laboratory by mixing it with hydrogen peroxide.
If it has catalase it will bubble.
3 Main enzymes that break down ROS - Answers -Superoxide dismutase
-Peroxides
-catalase
Anaerobic Jar - Answers chemical packs that remove oxygen and release carbon dioxide
clostridium difficile - Answers cannot survive in the presence of oxygen.
Passed
Differential Media - Answers make it easy to distinguish colonies of different microbes by changing the
color of the colony or the color of the medium.
Enrichment Media - Answers encourages growth of desired microbe that represent a fraction of the
organisms present in an inoculation.
Selective Media - Answers Inhibit growth of unwanted organisms and support thee growth of organisms
of interest.
Halotolerant - Answers Do not need a high concentration of salt to grow, but can still survive and divide
in the presence of salt.
Halophiles - Answers require high salt concentration for growth.
Thermophiles - Answers Optimal temep 50c
important for biotechnology
Listeria monocytogens - Answers Grows in refrigerators on/ in
-soft cheese
-deli meat
-hummus
-ice cream
Does not harm humans but can cross the placenta of a pregnant woman and kill the fetus.
Psychophile
Psychophiles - Answers Cold loving, optimal temp at 15c
Mesophiles - Answers Middle Loving, Optimal temp 20-45c
Most human pathogens.
, Normal microbiota
Helicbactor pylori - Answers neutrophile, survives in the stomach because it creates a micro
environment where the pH is nearly neutral.
Does it by urease with breaks down euro two form NH4+ and CO2
Alkaliphiles - Answers grow optimally at pH above 8.5
Acidophiles - Answers grow optimally at a pH of 5.5 or less.
Ex: Lactobacillus, contributes to the pH of the vagina of 4.0
Neutrophiles - Answers grow optimally at a pH one or two units within the neutral pH range.
Ex: E. coli
Most sensitive to pH change - Answers Proteins. Modifies the ionization of amino acid functional groups
and disrupts the hydrogen bonding.
causes the cell to flood.
Catalase and hydrogen peroxide reaction - Answers 2H2O2 -> 2H2O + O2
Catalase - Answers tested in the laboratory by mixing it with hydrogen peroxide.
If it has catalase it will bubble.
3 Main enzymes that break down ROS - Answers -Superoxide dismutase
-Peroxides
-catalase
Anaerobic Jar - Answers chemical packs that remove oxygen and release carbon dioxide
clostridium difficile - Answers cannot survive in the presence of oxygen.
