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Definitions |
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passive
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no cell energy
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psychrophile
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"cold lover" optimum temperature below 15 degrees C, capable of growth at 0 degrees Ccannot grow above 20 degrees C
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hypertonic
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higher concentration of water
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chemotroph
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energy obtained through chemicals
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satellitism
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when one member provides nutritional or protective factors needed by the other
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active transport
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the cell exerts energy to transport substances at a faster rate
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anaerobe
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lacks the metabolic enzyme system for using oxygen in respiration
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how microbes process oxygen
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As oxygen enters into cellular reactions, it is transformed into several toxic prodects. To protect themselves against damage, most cells have developed enzymes that scavenge and neutralize these chemicals. If a microbe is not capable of dealing with to
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aerobe
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can use gaseous oxygen
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minimum temperature
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the lowest temperature that permits a microbe's continued growth and metabolism
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alkalinophiles
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live in areas with high levels of basic materials; hot pools, soil, etc.
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passive transport
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the cell does not expend extra energy for functions to occur
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3 categories of microbes in gas requirement
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1) those that use oxygen and detoxify it, 2) those that can neither use oxygen nor detoxify it, and 3) those that don't use oxygen, but can detoxify it
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barophiles
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bacteria strictly adapted to high pressures; so much so that they will rupture when exposed to normal atmospheric pressure
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active transport features
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-transport of nutrients against the diffusion gradient or in the same direction as the natural gradient but at a faster rate...-the presence of specific membrane proteins...-the expenditure of additional energy in the form of ATP-driven uptake
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categories of essential nutrients
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macronutrients and micronutrients
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osmotolerant
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microbes that adapt to wide concentrations of solutes
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obligate (strict) anaerobes
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lack the enzymes for processing toxic oxygen, they cannot tolerate any free oxygen in the immediate environment and will die if exposed to it
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effects of pH
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the majority of organisms live and grow in habitats between pH of 6 and 8
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obligate aerobe
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cannot grow without oxygen
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macronutrients
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required in relatively large quantities; carbon, hydrogen oxygen, nitrogen, phosphorus, sulfur
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parasites
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derive nutrients from the cells or tissues of a host
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osmosis
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diffusion of water through a selectively permeable membrane
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hypotonic
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lower concentration of water
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phototroph
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energy obtained through photosynthesis
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active
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cell energy
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gas requirements
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the atmospheric gases that influence microbial growth are oxygen (greatest impact) and carbon dioxide
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facultative anaerobe
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does not require oxygen and is capable of growing without it; metabolizes by aerobic respiration when oxygen is present, but in its absence it adopts an anaerobic mode of metabolism
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microaerophile
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does not grow at normal atmospheric concentrations of oxygen but requires a small amount of it in metabolism
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commensalism
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the member called the commensal receives benefits while its coinhabitant is neither harmed nor benefited
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mesophiles
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intermediate temperatures; most fall into range of 20-40 degrees C, but some can grow between 10-50. most human pathogens have optimum growth between 30-40
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capnophiles
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grow best at higher CO2 tensions than are normally present in the atmosphere
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essential nutrients
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any substance that must be provided to an organism
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thermophiles
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"heat lovers"; optimal growth at temperatures greater than 45 degrees C; live in soil and water associated with volcanic activity, compost piles, and habitats directly exposed to the sun
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halophiles
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require high concentrations of salt
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optimum temperature
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temperature that promotes the fastest rate of growth and metabolism
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symbiosis
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two organisms live together in a close partnership
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nutrition
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process by which nutrients are acquired from the environment and used in cellular activities
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facilitated diffusion
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utilizes a carrier protein in the membrane that will bind a specific substance
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maximum temperature
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the highest temperature at which growth and metabolism can proceed
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isotonic
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same concentration of solvent and solute
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adaptation to temperature
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microbial cells are unable to control their temperature and therefore assume the ambient temperature of their natural habitats.
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endocytosis
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carry substances into the cell by phagocytosis
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growth factor
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organic compounds that cannot be synthesized because they lack the genetics to make them themselves
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mutualism
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when organisms live in an obligatory but mutually benefiial relationship
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diffusion
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net movement of molecules down their concentration gradient by random thermal motion
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saprobes
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free-living microorganisms that feed primarily on organic detritus from dead organisms
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micronutrients
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present in smaller amounts; potassium, sodium, calcium, magnesium, iron, zinc, copper, nickle
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inorganic
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nutrients in an atom or simple molecule that contains elements other than carbon and hydrogen
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phagocytosis
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pseudopods engulf substances and disolved into the vessicles
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group translocation
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couples the transport of a nutrient with its conversion to a substance that is immediatetly useful inside the cell
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organic
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nutrients contain at least some combination of carbon and hydrogen atoms
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aerotolerant anaerobes
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do not utilize oxygen but can survive and grow in its presence
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