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Cards In This Set
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What are we talking about when we talk about bacterial growth?
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The increase in bacterial numbers NOT about the increase of size of the individual cells.
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How does bacteria divide?
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Bacteria divides ASEXUALLY and by BINARY FISSION
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Name the four factors that influence bacterial growth
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Temperature, pH, oxygen availability, osmotic pressure
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What temperature does most organisms grow well at?
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The temperature favored by humans, 37C or 98.6F
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What is bacterias range of temperature to grow?
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Most bacteria grow only with a limited range of temperature, their max & min only about 30C degrees apart.
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Describe psychrophiles (temperature preference)
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Cold loving. grow between -10 and 15C
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Describe psychotrophs
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Group of spoilage microorganisms (faculative psychrophiles) grown between 0 & 30
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Describe mesophiles
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Most microorganisms belong to this group (moderate temp loving)
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Describe thermophiles
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Heat-loving. optimum temp between 40 & 70 C. optimum: 60 C
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Describe hyperthermophiles
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Optimum temp between 65 & 110C . Optimum: 95C. members of Archae
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What are the three temperatures do microorganisms grow at?
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Each microorganism grows at a particular minimum, optimum and maximum temperature. Optimum is when the species grows best.
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What is the most common method of preserving food?
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Refrigeration (<40F/4C). It is based on the principle that microbial reproduction decrease at low temperatures. Microbes can survive at freezing temperatures, but they gradually decline in number.
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Can Microbes survive at freezing temperatures?
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Yes, but they gradually decline in numbers
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Name the two types of bacteria that can grow on food.
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Pathogenic microorganisms and spoilage organisms
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What causes forborne illnesses. Will grow rapidly at "danger zone temperature" but they do not necessarily affect the taste and odor of food, so one cant tell if the food is contaminate
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Pathogenic bacteria
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