MICROBIOLOGY EXAM 2 CH. 6 – 9 STUDY GUIDE
Microbial Growth - Answers - The increase in numbers of microbes resulting in a
discrete colony
Heterotrophy - Answers - Eat food. They acquire carbon from organic molecules
Autotrophy - Answers - Make food. They make carbon from inorganic CO2
Obligate anaerobe - Answers - Oxygen is deadly to them. They lack the enzyme to
neutralize oxygen.
Obligate aerobe - Answers - They require oxygen for survival
Facultative anaerobe - Answers - Can grow with or without oxygen
Toxic oxygen - Answers - Singlet oxygen or H2O2 forms during aerobic respiration and
can damage proteins or DNA
How microbes deal with toxic oxygen - Answers - They make enzymes like catalase to
neutralize the toxic oxygen
Growth factors - Answers - Substances, like vitamins, that can't be synthesized by the
organism but are required for growth
Cells in extreme heat - Answers - Extreme heat denatures the proteins and membranes
causing them to become too fluid and leak
Psychrophile - Answers - Bacteria that grow in very cold temperatures. Don't cause
disease by can cause food spoilage
Mesophile - Answers - Bacteria that grow in moderate temperatures like the human
body that cause disease
Thermophile - Answers - Bacteria that grow in high temperatures like hot springs and
compost piles
Hyperthermophile - Answers - Bacteria that grow in extremely hot environments like
boiling volcanic geysers
Acidophile - Answers - Bacteria and fungi that grow in acid environments that can cause
disease
, Alkalinophile - Answers - Bacteria that grow in alkaline environments like soil or water
Osmotic Pressure - Answers - Pressure exerted on the inside of the cell outward due to
an influx of water
Osmotic pressure affect on bacteria cell - Answers - Bacteria can resist a hypotonic
environment. Hypertonic environments can kill a bacteria from dehydration of the
bacteria cell
Hypotonic - Answers - Low solute concentration in the cell
Hypertonic - Answers - High solute concentration in the cell
Isotonic - Answers - Equal concentration of solutes inside and outside of the cell
Symbiotic Relationship - Answers - Organisms with a nutritional relationship
Mutualistic Symbiotic Relationship - Answers - When the organisms are dependent on
one another
Commensal Symbiotic Relationship - Answers - One organism benefits while the other
is unharmed
Parasitisitic Symbiotic Relationship - Answers - One organism is harmed while another
benefits
Biofilms - Answers - Slimy layer of bacteria, fungi and protozoan growing together.
Microorganisms are more harmful as part of a biofilm
Culturing bacteria - Answers - Growing microorganisms in some type of growth media
Pure culture - Answers - A culture that contains a single species
Aseptic technique - Answers - Carrying out techniques that prevent bacterial
contamination. Reduces or minimizes the transmission of microorganisms.
Streak plates are used for - Answers - The isolating of mixed cultures
Defined media - Answers - The exact composition is known. Used to grow specific
microorganisms with specific requirements
Complex media - Answers - Some components are unknown. A general purpose media
used to grow most microorganisms.
Microbial Growth - Answers - The increase in numbers of microbes resulting in a
discrete colony
Heterotrophy - Answers - Eat food. They acquire carbon from organic molecules
Autotrophy - Answers - Make food. They make carbon from inorganic CO2
Obligate anaerobe - Answers - Oxygen is deadly to them. They lack the enzyme to
neutralize oxygen.
Obligate aerobe - Answers - They require oxygen for survival
Facultative anaerobe - Answers - Can grow with or without oxygen
Toxic oxygen - Answers - Singlet oxygen or H2O2 forms during aerobic respiration and
can damage proteins or DNA
How microbes deal with toxic oxygen - Answers - They make enzymes like catalase to
neutralize the toxic oxygen
Growth factors - Answers - Substances, like vitamins, that can't be synthesized by the
organism but are required for growth
Cells in extreme heat - Answers - Extreme heat denatures the proteins and membranes
causing them to become too fluid and leak
Psychrophile - Answers - Bacteria that grow in very cold temperatures. Don't cause
disease by can cause food spoilage
Mesophile - Answers - Bacteria that grow in moderate temperatures like the human
body that cause disease
Thermophile - Answers - Bacteria that grow in high temperatures like hot springs and
compost piles
Hyperthermophile - Answers - Bacteria that grow in extremely hot environments like
boiling volcanic geysers
Acidophile - Answers - Bacteria and fungi that grow in acid environments that can cause
disease
, Alkalinophile - Answers - Bacteria that grow in alkaline environments like soil or water
Osmotic Pressure - Answers - Pressure exerted on the inside of the cell outward due to
an influx of water
Osmotic pressure affect on bacteria cell - Answers - Bacteria can resist a hypotonic
environment. Hypertonic environments can kill a bacteria from dehydration of the
bacteria cell
Hypotonic - Answers - Low solute concentration in the cell
Hypertonic - Answers - High solute concentration in the cell
Isotonic - Answers - Equal concentration of solutes inside and outside of the cell
Symbiotic Relationship - Answers - Organisms with a nutritional relationship
Mutualistic Symbiotic Relationship - Answers - When the organisms are dependent on
one another
Commensal Symbiotic Relationship - Answers - One organism benefits while the other
is unharmed
Parasitisitic Symbiotic Relationship - Answers - One organism is harmed while another
benefits
Biofilms - Answers - Slimy layer of bacteria, fungi and protozoan growing together.
Microorganisms are more harmful as part of a biofilm
Culturing bacteria - Answers - Growing microorganisms in some type of growth media
Pure culture - Answers - A culture that contains a single species
Aseptic technique - Answers - Carrying out techniques that prevent bacterial
contamination. Reduces or minimizes the transmission of microorganisms.
Streak plates are used for - Answers - The isolating of mixed cultures
Defined media - Answers - The exact composition is known. Used to grow specific
microorganisms with specific requirements
Complex media - Answers - Some components are unknown. A general purpose media
used to grow most microorganisms.
