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20 Cards in this Set
- Front
- Back
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Cardinal Temperatures |
minimal,optimal & maximal temperatures at which a bacterium can GROW |
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Psychrophiles |
- can ONLY growat temperatures less than20°C - typicalrange -5°C to 20°C (32-68°F) |
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Psychrotrophs |
• typical range for growth 0°C to 30°C(23-86°F) •psychrotrophic bacteria can be found insoils, surface water and in foods •psychrotrophs can behuman pathogens |
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Psychrophiles |
•80% of all bacteria can grow at ≤ 10°C •psychrophilicbacteria can be found in alpine soils, icefields and oceans (marine water < 5°C)•psychrophiles are NOThuman pathogens |
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Mesophiles |
•typical range for growth ~15°C to ~40°C(59-113°F) •optimaltemperature forgrowth is approximately normal human body temperature•mesophilic bacteria can behuman pathogens that cause disease |
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Thermophiles |
• typical range for growth ~40°C to ~75°C(104-167°F) - Thermophiles can be found growing in hot springs |
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Hyperthermophiles or Extreme thermophiles |
•typical range for growth ~65°C to ~110°C(149-230°F) •hyperthermophiles canbe isolated from ocean floor thermal vents/ridges |
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Acidophiles |
•grow well in acidic environments at a pH of ≤ 4.5-5.5 - Can be found growing in such places as acid mine drainage and the stomach (stomach acid pH 1-2) |
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Alkaliphiles |
- Grow well in basic/alkaline environments at a pH of ≥8-8.5 - Canbe found in the soil of alkali flats or in places like the shores of Mono Lake,California where the pH is 10 |
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Neutrophiles |
•Growwell at a neutral pH of between 5.5 and 8•Mosthuman pathogens are neutrophilessince most bodily fluids are at a neutral pH - Human blood pH 7.4 |
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Turgor Pressor |
- Thepressure inside a cell that is required for survival - If the correct turgorpressure is not maintain a bacterium could: 1. Lysis - Cell rupture 2. Plasmolysis = cell shrinkage |
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Osmosis |
Themovementof water froman area of lowsolute concentration toan area of highsolute concentration in order to achieve equilibrium |
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Osmotic Pressure |
Theforcewithwhich H2O flows froman area of lowsolute concentration toan area of highsolute concentration |
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3 types of osmotic environments abacteria could encounter |
1. Hypotonic 2. Hypertonic 3. Isotonic |
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Hypotonic |
•highersolute conc’ninside the cell than outside•low osmotic pressure •H2O moves into thecell •cellwill lysis |
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Hypertonic |
•lowersolute conc’ninside the cell than outside •high osmotic pressure •H2O moves out ofthe cell •cellwill plasmolysis |
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Isotonic |
•equal solute conc’ninside and outside the cell •H2O moves in and out of the cell equalrate |
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Halophiles (salt loving) |
Certainbacteria grow optimally at salt concentrations > 3% |
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Extreme Halophiles |
asub-group of halophiles thatcan ONLY survive at salt concentrationsfrom ~15 to 25% |
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Osmotolerant bacteria |
bacteriathat can survive and grow over a wide range ofsalt concentrations |
