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Flashcards in Principles of Micro 4 Deck (52)
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what are the two types of cell inclusions in bacteria

glycogen and polyphosphate


where are the cell inclusion found and what are their functions

glycogen: found in many species, carbon and energy storage

polyphosphate: found in many species, phosphate storage


are endospores mainly gram pos or gram neg

main gram pos
just recently found one gram neg one


what is the importance of endospores

they shut down protein, enzymatic, and macromolecular synthesis and wait

they are important for heat, chemical, and radiation resistance for bacteria


what are the three locations for bacterial cell in endospores

terminal - all the way to one end
central - in the middle
subterminal - almost all the way to one end


name the endospore formers

c. difficile
c. botulinum
c. tetani
b. cereus


what is so important about c. difficile

significant for infection control


describe sporulation and germination

in harsh environment, bacteria cells undergoes sporulation where it replicates and produces a spore while the original cell dies (take 6-8hrs)

then in favorable environment, the spore germinates back to bacteria taking 1 - 2 hrs


what are components that influence growth of microorganism

temperature, pH, water, carbon and energy sources, trace elements


how does temperature influence growth rate of microorganism

there is an optimum range for microorganism growth

also there is a min and max temp where microorganism do not grow


name the temperature categories in which microorganisms fall under; what the optimum temp is in degree celsius; and if medically significant

psychrotrophs and psychrophiles - 15 oC - No
Mesophiles - 20-40 oC - Yes
thermophiles - 50-60 oC - No


what is the difference between pyschrotrophs and psychrophiles

psychrophiles are cold loving and actually handle temperatures as low as 2 - 3 oC while psychrotrophs can tolerate the cold weather so their optimum is only 15 oC


random pop quiz: what is a firmly attached polysaccharide layer that is located external to the cell wall/outer membrane which enables bacterial evasion one of the host non specific defenses



list the pH categories in which microorganisms fall under and what pH they can handle

extreme acidophiles: 0-2
acidophiles: 3 - 5
neutrophiles: 6 -8
alkalophiles: 9 - 11
extreme alkalophiles: 12-14


list the ranges of water availability in which microorganisms can thrive/not thrive

.93 - .98: no growth of gram positive bacteria
.97 - no growth of gram neg bacteria
less than .93 - most spoilage due to yeast and fungi
less than .9 - most bacterial unable to grow
less than .6 - no microbial growth


what do all organisms need

carbon and energy source


what are way in which organisms can get energy

chemotrophs - chemical energy
phototrophs - light energy


examples of phototrophs

plants, algae, photosynthetic bacteria


what are two types of chemotrophs

chemolithotrophs - use inorganic sources of carbon

chemoorganotrophs (heterotrophs) - use organic sources of carbon (most bacteria)


examples of chemoorganotrophs aka heterotrophs

bacteria, fungi, protozoa, humans


what sources can you get the following elements from: carbon, oxygen, nitrogen, hydrogen, phosphorus, sulfur

carbon (50%) - cellular material
oxygen (20%) - cell material and cell water, 02 is an electron acceptor in aerobic respiration
nitrogen - AA, nucleic acid nucleotides, coenzymes
hydrogen - organic compounds and water
phosphorus - nucleic acids, nucleotides, phospholipids, LPS, techoic acid
sulfur - glutathione, cysteine, methionine, several coenzymes


what are trace elements usually needed by microorganisms

usually metal ions - zinc cobalt for ex
enzymes needed in energy generation
organic growth factors like vitamins and minerals


do all microorganisms need organic growth factors

no some of them synthesize their own


what pathogen requires nicotinamide

bordetella pertussis


what pathogen requires X and V factor

haemophilus sp.


in an unshaken culture, describe where each type of microorganisms in relation to their oxygen requirements

top only - obligate aerobes
evenly distributed - facultative anaerobe and aerotolerant anaerobe
slightly below surface - microaerophile


what is difference between facultative anaerobe and aerotolerant anaerobe

facultative - use O2 if present but if not will use something else

aerotolerant - indifferent to O2, even in their presence they won't use them, need non O2 requirements


what are obligate anaerobes and why are they not present in the unshaken cultures

they must be in an area without any oxygen or they will not grow

not in unshaken culture because they only grow in specially prepared media/conditions


which group of microorganisms use catalase and superoxide dismutase

obligate aerobes and most facultative anaerobes


which group of microorganisms use only superoxide dismutase

most aerotolerant anaerobes