Microbiology Exam 3 Review Assesment Test With All Answers.pdf

Microbiology Exam3ReviewAssesmentTest v v v v v




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What two categories can requirements for microbial growth to be divided into? - CORRECT ANSWER✔✔
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Physical

Chemical



Know all the classifications of microorganisms based on temperture requirements and the temp ranges for
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each group. - CORRECT ANSWER✔✔Psychrophiles -10 to 20 degrees C
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Mesophiles 25 to 40 degress C v v v v v




Thermophiles 50 to 100 degrees C v v v v v




Acidophiles (acid) v




Halophiles (Salt) v




Know Micro-organisms Ability to grow in acid or salt? - CORRECT ANSWER✔✔Acidophiles-tolerant to PH as
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low as 1.0
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Halophiles

PH most bacteria like 6.5-7.5
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Know the effect of low and high osmotic pressure on a bacteria cell wall. - CORRECT ANSWER✔✔Low Osmotic
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pressure - expand
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High Osmotic Pressure - Shrink
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, What is plasmolysis? - CORRECT ANSWER✔✔Shrinkage of the cells cytoplasm
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-------osmotic loss of H2O because of/greater # v v v v v v v




of solutes in surrounding medium.
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Know all terms for organsisms based o2 requirements - CORRECT ANSWER✔✔Obligate aerobes - growth only
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occurs where high o2 concentration
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Facultative anarobes - growth best where most o2 is present v v v v v v v v v




Obligate anarobes - growth only occurs where there is no o2
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Aero tolerant anarobes - growth occurs evenly - o2 has no effect
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Microaerophiles-growth occurs only where low o2 concentration v v v v v v




Know phases of growth for bacterial cells and what is going on for each phase - CORRECT ANSWER✔✔Lag
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phase: no growth but there is metabolic activity
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Log Phase: exponential growth occurs
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Stationary phase: period of equilibrium v v v v v




Death phase: population decreases at a logarhythmic rate
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What bacteria enzyme converts peroxide into water and o2? - CORRECT ANSWER✔✔Catalase
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What does a candle jar provide? - CORRECT ANSWER✔✔Provides co2 environment of approx 3%
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What is a spectrophotometer used for? - CORRECT ANSWER✔✔instrument used to measue turbidity
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know chemicals used for antisepsis or de-germing - CORRECT ANSWER✔✔alcohol swab
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What is hydrogen peroxide classified as? - CORRECT ANSWER✔✔peroxygenes
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