IUPUI K356 EVALUATION EXAMS ANSWERS AND
QUESTIONS SET A+
✔✔Growth Curve - ✔✔A graph showing the rate at which cells grow when put on a new
medium. Consists of 4 phases: Lag, Log, Stationary and Death.
✔✔Growth Rate - ✔✔number of generations per unit time
✔✔Generation Time - ✔✔Defined as the amount of time it takes to double. Also called
"Doubling Time".
✔✔Colony Forming Units (CFU's) - ✔✔This is what we are actually counting on an agar
plate. It represents cells that can actually grow to form a colony. It's important because it
means we are only counting vegetative cells, and not cells that aren't growing.
✔✔Spectrophotometry - ✔✔-Tool used to measure the density of cell growth in broth.
It's another way to count cells in a medium.
-optical density
✔✔What does too high and too low of temperatures do to microbes? - ✔✔-Too high =
proteins unfold, membranes disintegrate
-Too low = no metabolic activity
✔✔Psychrophile - ✔✔-bacteria that prefer cold, thriving at temperatures between 0 C
and 20 C, 15 C is optimum
-cold stable proteins and lipids
✔✔Psychrotolerant - ✔✔-organisms that can grow at 0°C but have optima of 20°C to
40°C
-food spoilage
✔✔Mesophile - ✔✔-moderate temperatures, 8-48 C
-pathogens
, ✔✔Thermophiles - ✔✔-45-80 C, optimal in 55-65 C
-Heat stable proteins, lipids
✔✔Hyperthermophiles - ✔✔can grow at extremely high temps, up to 122 C
✔✔Osmotolerant - ✔✔Microbes that can still grow when the tonicity of their environment
changes, but cannot grow in extremely hypertonic solutions. Example is Staph. aureus.
✔✔Halophile - ✔✔Microbes that require a high concentration of salt (0-12% NaCl)
✔✔Extreme halophile - ✔✔15-30% NaCl
✔✔Halotolerant - ✔✔a microorganism that does not require NaCl for growth but can
grow in the presence of NaCl, in some cases, substantial levels of NaCl
✔✔Acidophile - ✔✔Microbes that require very low pH (less than 5.5)
✔✔Neutrophile - ✔✔Microbes that require neutral pH (5.5<pH<8)
✔✔Alkaliphile - ✔✔Microbes that require very high pH (greater than or equal to 8)
✔✔Are microbial cells hypotonic or hypertonic? - ✔✔hypertonic
✔✔Osmophile - ✔✔live in high solute concentrations
✔✔Xerophile - ✔✔live in dry environments ("zero water")
✔✔Aerobe - ✔✔need oxygen to grow
✔✔Anaerobe - ✔✔no oxygen to grow
✔✔Facultative Anaerobe - ✔✔Microbes that can grow in the presence of oxygen, but
grow optimally without oxygen.
✔✔Aerotolerant anaerobe - ✔✔doesn't use O2, but tolerates it
✔✔Microaerophile - ✔✔Microbe that requires a small amount of oxygen to grow.
✔✔Piezophiles - ✔✔microbes that can survive in high atmospheric pressure (300-400
atm)
QUESTIONS SET A+
✔✔Growth Curve - ✔✔A graph showing the rate at which cells grow when put on a new
medium. Consists of 4 phases: Lag, Log, Stationary and Death.
✔✔Growth Rate - ✔✔number of generations per unit time
✔✔Generation Time - ✔✔Defined as the amount of time it takes to double. Also called
"Doubling Time".
✔✔Colony Forming Units (CFU's) - ✔✔This is what we are actually counting on an agar
plate. It represents cells that can actually grow to form a colony. It's important because it
means we are only counting vegetative cells, and not cells that aren't growing.
✔✔Spectrophotometry - ✔✔-Tool used to measure the density of cell growth in broth.
It's another way to count cells in a medium.
-optical density
✔✔What does too high and too low of temperatures do to microbes? - ✔✔-Too high =
proteins unfold, membranes disintegrate
-Too low = no metabolic activity
✔✔Psychrophile - ✔✔-bacteria that prefer cold, thriving at temperatures between 0 C
and 20 C, 15 C is optimum
-cold stable proteins and lipids
✔✔Psychrotolerant - ✔✔-organisms that can grow at 0°C but have optima of 20°C to
40°C
-food spoilage
✔✔Mesophile - ✔✔-moderate temperatures, 8-48 C
-pathogens
, ✔✔Thermophiles - ✔✔-45-80 C, optimal in 55-65 C
-Heat stable proteins, lipids
✔✔Hyperthermophiles - ✔✔can grow at extremely high temps, up to 122 C
✔✔Osmotolerant - ✔✔Microbes that can still grow when the tonicity of their environment
changes, but cannot grow in extremely hypertonic solutions. Example is Staph. aureus.
✔✔Halophile - ✔✔Microbes that require a high concentration of salt (0-12% NaCl)
✔✔Extreme halophile - ✔✔15-30% NaCl
✔✔Halotolerant - ✔✔a microorganism that does not require NaCl for growth but can
grow in the presence of NaCl, in some cases, substantial levels of NaCl
✔✔Acidophile - ✔✔Microbes that require very low pH (less than 5.5)
✔✔Neutrophile - ✔✔Microbes that require neutral pH (5.5<pH<8)
✔✔Alkaliphile - ✔✔Microbes that require very high pH (greater than or equal to 8)
✔✔Are microbial cells hypotonic or hypertonic? - ✔✔hypertonic
✔✔Osmophile - ✔✔live in high solute concentrations
✔✔Xerophile - ✔✔live in dry environments ("zero water")
✔✔Aerobe - ✔✔need oxygen to grow
✔✔Anaerobe - ✔✔no oxygen to grow
✔✔Facultative Anaerobe - ✔✔Microbes that can grow in the presence of oxygen, but
grow optimally without oxygen.
✔✔Aerotolerant anaerobe - ✔✔doesn't use O2, but tolerates it
✔✔Microaerophile - ✔✔Microbe that requires a small amount of oxygen to grow.
✔✔Piezophiles - ✔✔microbes that can survive in high atmospheric pressure (300-400
atm)
