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Microbiology > Chapter 11: Characyerizing and classifying prokaryotes > Flashcards

Chapter 11: Characyerizing and classifying prokaryotes Flashcards

1
Q

Prokaryotes

A

-the mot diverse group of organisms on the planet
-they are found everywhere on the planet (glaciers, hot springs, colons of animals, supersaturated brines)
-rarely capable of pathogenicity
-diverse morphologies

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2
Q

Bergey’s manual of systematic

A

-organizes taxonomy info for identification and cataloging microbes

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3
Q

Prokaryotes reproduce mostly by

A
  • asexual reproduction (more specific binary fission)
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4
Q

Ways prokaryotes reproduce

A
  1. binary fission (most common)
    2.snapping division (results in V arrangement or palisades)
  2. Budding
  3. Formation of asexual spores
  4. fragmentation
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5
Q

Steps in binary fission

A
  1. cell replicates its DNA
  2. The cytoplasmic membrane elongates, separating DNA molecules
  3. Cross wall forms and membrane invaginates
  4. Cross wall forms completely
  5. daughter cells
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6
Q

What are the reasons for different cell arrangement during binary fission?

A
  1. Number of planes
  2. separation vs non separation of daughter cells
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7
Q

How are some organisms named?

A

-Often named by shape and or arrangement of the cells

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8
Q

What does a single plane of division produce in cocci?

A
  • diplococci or streptococci
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9
Q

What do 2 plane divisions produce in cocci?

A

-tetrads

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10
Q

What do 3 plane divisions produce in cocci?

A

-Sarcina or staphylococci

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11
Q

Why are arrangements of bacilli less varied?

A

-they are less varied b/c they only divide along a single transverse plane

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12
Q

Archaeans lack what in their cell walls?

A

-they lack peptidoglycan in their walls, but they use proteins, glycoproteins, lipoproteins or other polysaccharides
-their cell membrane phospholipids have branched hydrocarbon chains

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13
Q

Archaeans reproduce by?

A

-asexual reproduction, more specifically binary fission, but also budding or fragmentation

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14
Q

Archean morphology

A

-usually cocci, bacilli, or spiral forms but some a pleomorphic

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15
Q

Do archeans cause disease?

A

no

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16
Q

Example of archeans

A

Extremophiles and methanogens

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17
Q

Thermophiles and Hyperthermophiles

A

-Their DNA, RNA, cytoplasmic membranes, and proteins do not function in typical environmental heat
Thermophiles need minimum temperature of 45 C while hyperthermophiles need over 80 C

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18
Q

Name two representative genera of Thermophiles and Hyperthermophiles

A

-Geogemma and pyrodictium

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19
Q

Haplophiles

A

-depend on a minimum 9% NACl to maintain their integrity of their cell walls but usually 17-23% to thrive while some need an upward of 35% saline
-have orange and red pigment to protect from UV light
-most studied is halobacterium salinarium

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20
Q

Methanogens

A

-they convert CO2/H2 gas and organic acids to methane gas and some convert organic wastes in pond, lakes, and ocean sediments to methane
-some live in colonies of animals and they are the primary source of environmental methane
-estimated to have produced 10 trillion tons of methane
-useful in sewage treatments by digesting sludge and make up 1/3 of the biomass in Antarctic waters

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21
Q

Who are the largest groups of archaea

A

mesophiles

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22
Q

Deeply branching bacteria

A

-scientists believe these organisms are similar to the earliest bacteria on the planet because they are
1. autotrophic
2. aquifex
3.deinococcus
-can withstand extreme exposure to radiation

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23
Q

Autotrophic

A

they live in habitats similar to those which scientists believe existed on early earth

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24
Q

aquifex

A

-is considered to represent earliest branch of bacteria b/c chemoautrophic, hyperthermophilic, anaerobic and obtains carbon from inorganic sources

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25
Deinococcus
-has an outer membrane similar to gram negatives, but stains gram positive
26
Phototrophs
contains photosynthetic lamellae, layers in the cell membrane used for photosynthesis
27
List the phototrophic organisms
1. Blue green bacteria 2. Nitrogen fixers 3. green and purple non-sulfur bacteria 4.green and purple sulfur bacteria
28
Blue-green bacteria
-formerly called blue-green algae, undergo oxygenic photosynthesis like algae and plants using chlorophyll a -they possible evolved into chloroplast (endosymbiosis) -ex: cyanobacteria
29
Nitrogen fixers
-reduce molecular nitrogen into fixed nitrate which is good for plants and then we get to use it. -this is how we get nitrogen into the food chain
30
Green and purple non-sulfur bacteria
-anoxygenic and derive electron from organic molecules to reduce CO2
31
Green and purple sulfur bacteria
-anoxygenic and derive electrons from oxidizing H2S to S
32
Clostridia
Bacilli, anaerobic, endospore producer, low G+C gram positive bacteria
33
what diseases does clostridia produce
1. botulinum (botulism) 2. perfringes (gangrene) 3. tetani (tetanus) 4. difficile (Dif. infection)
34
Veillonella
-closely related to clostridia and are involved in production or cause of dental caries
35
Bacillus thuringiensis
farmers friend
36
Bacillus polymyxa
antibiotics (polymyxin)
37
Bacillus licheniformis
antibiotics (bacitracin)
38
Bacillus anthracis
-causes anthrax
39
Listeria
-transplacental, can kill a gestating fetus -why pregnant women cannot eat certain foods
40
Lactobacillus
microbial antagonism and industrial uses -produces lactic acid -can cause yeast infections
41
streptobacillus and enterococcus
-both are pathogenic -enterococcus can be found in colon
42
Staphyloccocus epidermidis and aureus
-found on skin surface
43
MRSA
methicillin resistant staph aureus
44
Actinomycetes
-grow as branching filaments, look fungi like -they are "spore formers" (asexual) -Gram high G+C gram positive bacteria
45
actinomyces
normal flora of the mouth but opportunistic and potentially harmful -Gram high G+C gram positive bacteria
46
nocardia
-is able to degrade environmental pollutants -Gram high G+C gram positive bacteria
47
streptomyces
is natures nutrient recyclers in soil -Gram high G+C gram positive bacteria
48
Examples of bacteria that produce important antibiotics
-chloranphenicol, tetracycline, and erythromycin -made from Gram high G+C gram positive bacteria
49
Gram negative proteobacteria
-the largest and most diverse group of bacteria
50
Name the six distinct classes of proteobacteria
1. alphaproteobacteria 2.betaproteobacteria 3. gammaproteobacteria 4. deltaproteobacteria 5. epsilonproteobacteria 6 zetaproteobacteria
51
Azosprillium
-grows on the outer surface of plant roots
52
rhizobium
grows within the roots of legumes and stimulates nodule production
53
nitrifying bacteria
-convert NH3 and NH4 into NO3 (nitrate) -it is easier for a plant to use nitrate which we eat and get the nitrogen from the plant -ex; nitrobacter
54
Examples of alphaproteobacteria
1. nitrogen fixers 2. nitrifying bacteria 3. acetobacter and gluconobacter 4. caulobacter 5. agrobacterium
55
Acetobacter and Gluconobacter
-are acid producer (acetic acid and gluconic acid)
56
Caulobacter
unusual growth and reproduction (including prostheca (used to make prosthetics), swarmer cells and rosette)
57
Agrobacterium
-causes plant gall (tumor) formation and is used as a delivery vehicle (vecctor) to create transgenic plants -GMO's in biotechnology, recombinant DNA technology
58
Caulobacter life cycle
1. A cell that has attached to a substrate with its prostheca 2. grows until it has doubled in size, at which time it produces a flagellum at its apex and then it divides by asymmetric binary fission 3. the flagellated daughters cell which is called a swarmer cell then swims away. The swarmer cell can either attach to a substrate with new prostheca 4. or attach to the other swarmer cell to form a rosette cell * this repeats every two hours
59
Non-pathogenic betaproteobacteria examples
1. thiobacillus 2, zoogloea 3. sphaerotilus
60
thiobacillus
oxidize S and H2S into SO4 (sulfate) to recycle sulfur in the environment
61
zoogloea
-sewage flock (flocculate) sinks, and this helps purify sewage in sewage treatment processing
62
sphaerotilus
-sewage flock rises and this impedes purifying sewage
63
Examples of gammaproteobacteria
1. methane oxidizers 2.glycolytic facultative anaerobes 3. gammaproteobacteria nitrogen fixers
64
Methane oxidizers
-use NH4 as a carbon source -ex: methylococcus
65
Glycolytic facultative anaerobes
-are the largest group of gammaproteobacterial and pathogenically a big group -includes family Enterobacteriaceae (gram - facultative anaerobes)( e.coli)
66
azotobacter and azomonas
-are both nitrogen fixers but they do not associate with the plant roots like azospirillum and rhizobium
67
Deltaproteobacteria examples
1. desulfovibrio 2. bdellovibrio 3. myxobacteria
68
desufovibrio
another sulfur recycler
69
bdellovibrio
-pathogenic to other gram - bacteria
70
myxobacteria
"spore former" (myxospores) for asexual reproduction
71
Bdellovibrio life cycle
1.A free Bdellovibrio swims until it attaches via fimbriae to a Gram-negative bacterium. it rapidly drills through the cell wall of its prey by secreting hydrolytic enzymes 2. Once inside, Bdellovibrio lives in the periplasmic space. It kills its host by disrupting the host’s cytoplasmic membrane and inhibiting DNA, RNA, and protein synthesis. 3. The invading bacterium uses the nutrients released from its dying prey and grows into a long filament. 4. Eventually, the filament divides into as many as nine smaller cells at once , each of which when released from the dead cell, produces a flagellum and swims off to repeat the process. Undergoing multiple fissions to produce many offspring is a rare form of reproduction.
72
Myxobacteria life cycle
1.Vegetative myxobacteria glide on slime trails through their environment, digesting yeasts and other bacteria or scavenging nutrients released from dead cells. When nutrients and cells are plentiful, the myxobacteria divide by binary fission; when nutrients are depleted, however, they aggregate by gliding into a mound of cells. 2. Myxobacteria within the mound differentiate to form a macroscopic fruiting body ranging 3. Some cells within the fruiting body develop into dormant myxospores that are enclosed within walled structures called sporangia 4.The sporangia release the myxospores, which can resist desiccation and nutrient deprivation for a decade or more. When nutrients are again plentiful, the myxospores germinate and become vegetative cells.
73
Bacteroids examples
1. bacteroides 2. cytophaga
74
bacteroides
-common in human intestinal flora
75
cytophaga
common aquatic organisms that degrade sewage and cause damage to wood in water

Microbiology (13 decks)

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