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30 terms

Chapter 7

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essential nutrients
any ingredient such as certain amino acid, fatty acid, vitamin, or mineral that cannot be formed by an organism and must be supplied in the diet
macronutrients
a chemical substance required in large quantities (ex- phosphate)
micronutrients
a chemical substance required in small quantities (ex- trace metals)
growth factor
an organic compound such as a vitamin or amino acid that must be provided in the diet to facilitate growth; an essential nutrient
autotroph
a microorganism that requires only inorganic nutrients and whose sole source of carbon is carbon dioxide
heterotroph
an organism that relies upon organic compounds for its carbon and energy needs
photoautotroph
an organism that utlilizes light for its energy and carbon dioxide chiefly for its carbon needs
chemoautotroph
an organism that relies upon inorganic chemicals for its energy and carbon dioxide for its carbon
saprobe
a microbe that decomposes organic remains from dead organisms
parasite
an organism that lives or within another organism (the host), from which it obtains nutrients and enjoys protection
halophile
a microbe whose growth is either stimulated by salt or requires high concentration of salt for growth
alkalinophile
bacteria that likes basic of alkaline solution
neutrophile
bacteria that likes a neutral solution
acidophile
bacteria that likes an acidic solution
aerobe
a microorganism that lives and grows in the presense of free gaseous oxygen
anaerobe
a microorganism that grows best, or exclusively, in the absense of oxygen
facultative anaerobe
can live with or without the presense of oxygen
psychrophile
a microorganism that thrives at low temperatures with an optimum temperature at 0-15 deg. cel.
mesophile
microorganisms that grow at intermediate temperatures
thermophile
microorganisms that thrive at a temperature of 50 deg. cel. or higher
symbiosis
an intimate association between individuals from two species; used as a synonym for mutalism
parasitism
a relationship between two organisms in which the host is harmed in some way while the colonizer benefits
commensalism
an unequal relationship in which one species derives benefit without harming the other
mutalism
organisms living in an obligatory, but mutally benefitical relationship
binary fission
the formation of two new cells approximately equal size as the result of parent cell division
generation time
time requried for a complete fission cycle
lag phase
the early phase of population growth during which no signs of growth occur
log phase
maximum rate of cell division which growth is geometric in its rate of increase; also called exponenetial growth
stationary growth phase
phase when the population enters a survival mode in which cells stop growing or grow slowly
death or decline
end of cell growth due to lack of nutrition, depletion of environment, and accumulatio of wastes; population of cells begin to die