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Micro Bio 2 test > Chapter 3.6-4 > Flashcards

Chapter 3.6-4 Flashcards

1
Q

what are Capsules and Slime Layers?

A

Gel-like layer outside cell wall that protects or allows attachment to surface

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2
Q

Capsule:

Slime layer:

A

Capsule-distinct, gelatinous

Slime-diffuse, irregular

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3
Q

What are slime and capsules made of an how does it help

A 
Allow bacteria to adhere to surfaces
Once attached, cells can grow as biofilm
Polysaccharide-encased community
Example: dental plaque
Some capsules allow bacteria to evade host immune system
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4
Q

Flagella

A

involved in motility
Spin like propellers to move cell
Some are important in diseases
Numbers and arrangements help with identifying

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5
Q

Peritrichous

A

having flagella uniformly distributed over the body

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6
Q

Polar flagellum:

A

single flagellum at one end of cell

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7
Q

some bacteria have a lophotrichous

A

Some bacteria have tuft at one or both ends:having two or more flagella at one end

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8
Q

Where does the flagellum get its energy?

A

Mot genes harvest the Proton Motive Force in order for the Flagellum to rotate

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9
Q

Chemotaxis and Movement is series of runs and tumbles

A

Chemotaxis is movement of an organism in response to a chemical stimulus…….runs and tumbles

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10
Q

…… are shorter than flagella

Function in surface attachment and adhesion for..

A

pili….. surface attachment and adhesion… bacteria

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11
Q

Chromosome forms in gel-like region:

A

the nucleoid
***Single circular double-stranded DNA
Packed tightly via binding proteins and supercoiling

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12
Q

Plasmids are

A

circular, supercoiled, DNA

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13
Q

Ribosomes are involved in

A

Ribosomes are involved in protein synthesis

Facilitate joining of amino acids

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14
Q

Cytoskeleton: *Involved in cell

A

internal protein framework
Once thought bacteria lacked this
Bacterial proteins similar to eukaryotic cytoskeleton have been characterized…both actin and myosin-like
** division and controlling cell shape

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15
Q

Storage granules

A

accumulations of polymers

Synthesized from nutrients available in excess

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16
Q

Sporulation

A

formation of spores is triggered by carbon, nitrogen limitation

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17
Q

Prokaryotic cells divide by

A

binary fission

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18
Q

Exponential growth:

A

population doubles each division

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19
Q

Generation time is time it takes to for

A

the population to double

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20
Q

And..Environmental conditions sushi as ……. influence generation time

A

such as nutrients and temperature also

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21
Q

Nt = N0 x 2^n what does t 0 n stand for

A 
Nt = number of cells in population at time t
N0 = original number of cells in population
n = number of divisions
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22
Q

The power of exponential growth

A

***generation time depends on the bacterial species (genetics) and its growth conditions

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23
Q

Cells sense changes, adjust to surroundings
Synthesize compounds useful for growth
Most live in

A

Most live in polysaccharide encased communities
Termed biofilms
Ie stuff on rocks

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24
Q

Biofilms have characteristic architectures

A

Channels through which nutrients and wastes pass

Cells communicate by synthesizing chemical signals

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25
Q

Biofilms have important implications

A

Dental plaque leads to tooth decay, gum disease
Many infections (e.g., ear infections, respiratory infections in cystic fibrosis patients)
Industrial concerns: accumulations in pipes, drains
Biofilm structure shields microbes growing within
May be hundreds of times more resistant to antibiotics

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26
Q

Some synthesize toxic compounds to inhibit competitors called

A

Bacteriocins

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27
Q

Prokaryotes grown on agar plates or in tubes or flasks of broth
Closed systems

A

-Nutrients not renewed; wastes not removed Yields a growth curve

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28
Q

Open system required to maintain continuous

A

growth
Makes use of a chemostat
Termed continuous culture
Nutrients added, wastes removed continuously

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29
Q

a chemostat is..

A

is a bioreactor to which fresh medium is continuously added, while culture liquid is continuously removed to keep the culture volume constant.[1][2] By changing the rate with which medium is added to the bioreactor the growth rate of the microorganism can be easily controlled.Continually drips fresh medium into culture
Drips gases (O2) if needed
Equivalent volume removed
Contains cells, wastes, spent medium
Nutrient content and speed of addition can be controlled
Achieve constant growth rate and cell density for prolonged periods of time
**Produces relatively uniform ***population for study and/or isolation of primary or secondary metabolites

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30
Q

Draw the growth curve and explain each step

A

:) Chpt 4 slide 11

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31
Q

what stage are bacteria most sensitive to anti antibiotics

A

Exponential (log) phase

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32
Q

Stationary phase

Nutrient levels too

A

low to sustain log growth
Total numbers of bacteria in the population remain constant…for every cell that divides, two cells die
Some die, release contents; others grow using these as nutrients

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33
Q

Death phase

A

Total number of viable cells decrease rapidly

Cells die at constant rate

34
Q

Important differences based on location (position) of the cell in the colony

A

Position of single cell determines its environment
Edge of colony has O2, nutrients
Center of colony has depleted O2, very few nutrients
Accumulation of potentially toxic wastes, including acids
Colony may range from exponential growth at edges to death phase in center

35
Q

Termed extremophiles; most are in the Domain …..

Major conditions that influence growth:

A

Archaea

Temperature
Oxygen
pH
Water availability

36
Q 
Ranges of temp for
Psychrophile: 
Psychrotroph:
Mesophile: 
Thermophiles: 
Hyperthermophiles:
A 
Psychrophile: –5° to 15°C
Psychrotroph: 20° to 30°C
Mesophile: 25° to 45°C
Thermophiles: 45° to 70°C
Hyperthermophiles: 70° to 110°C
37
Q

Proteins of thermophiles resist

A

denaturing
Thermostability comes from amino acid sequence
Number and position of bonds, which determine structure of the protein

38
Q

Temperature and food preservation

Refrigeration (~4°C) slows spoilage

A

by limiting growth of otherwise fast-growing mesophiles
Psychrophiles, psychrotrophs can still grow, but slowly
Freezing preserves food; but is not effective at killing microbes

39
Q

Temperature and pathogens

A

Temperature of different parts of human body differs
E.g., Hansen’s disease (leprosy) involves coolest regions (ears, hands, feet, fingers) due to preference of M. leprae
Syphilis…Treponema pallidum and plague too

40
Q

Aerobes –

A

undergo aerobic respiration and require oxygen as the terminal electron acceptor in ETS

41
Q

Anaerobes –

A

do not use aerobic metabolism; toxic forms of oxygen are harmful to these bacteria

42
Q

Facultatives

A

– can maintain life via fermentation or anaerobic respiration or by aerobic respiration***

43
Q

Aerotolerant anaerobes –

A

do not use aerobic metabolism but have enzymes that detoxify oxygen’s poisonous forms

44
Q

Microaerophiles –

A

aerobes that require oxygen levels from 2 to 10%, use aerobic respiration, and have a limited ability to detoxify hydrogen peroxide and superoxide radicals

45
Q

the toxic forms of Oxygen Name and symbol

A

Superoxide anion O2-

Hydrogen peroxide H2O2

Hydroxyl radical OH.

46
Q

Enzymes that protect against toxic forms of oxygen

A

Catalase H2O2

Superoxide dismutase O2-

Peroxidase H2O2

47
Q

neutrophiles thrive in
Acidophiles grow optimally at pH
Alkaliphiles

A

Range of pH 5 to 8;
below 5.5
grow optimally at pH above 8.5

48
Q

All microorganisms require wat for growth

A

water

49
Q

If solute concentration is higher outside of cell, water diffuses

A

out (osmosis)

***For this reason Salt and Sugar are used to preserve food

50
Q

Carbon source distinguishes different groups
Heterotrophs use
Autotrophs use

A

organic carbon

inorganic carbon as CO2

51
Q

fastidious

A

“picky eaters”) have complicated nutritional requirements

52
Q

Phototrophs extract energy from

A

obtain energy from sunlight

Plants, algae, photosynthetic bacteria

53
Q

Chemotrophs extract energy from

A

chemicals- organic compounds

54
Q

Photoautotrophs:

A

energy from sunlight; carbon from CO2

55
Q

Photoheterotrophs:

A

energy from sunlight; carbon from organic compounds

56
Q

Complex media

Chemically defined media

A

-Complex media (undefined) contains variety of ingredients
Exact composition highly variable
Often an enzymatic digest of proteins
-Chemically defined media (synthetic) composed of exact amounts of pure chemicals

57
Q

Differential media

A

(through color) contains substance that microbes change in an identifiable way

58
Q

Selective media inhibits growth of certain

A

species & not others.

59
Q

Aerobic

A

Most obligate aerobes and facultative anaerobes can be incubated in air
Many medically important bacteria (e.g., Neisseria, Haemophilus) grow best with increased CO2
Some are capnophiles, meaning they require increased CO2

60
Q

Microaerophilic

A

Require lower O2 concentrations

61
Q

Anaerobic:

A

obligate anaerobes sensitive to O2
Anaerobic containers or jars ,useful if microbe can tolerate brief O2 exposures; can also use semisolid culture medium containing reducing agent (e.g., sodium thioglycolate)

Anaerobic glove chamber is the only way to culture strict

62
Q

Direct cell counts:

A

total numbers (living, plus dead)

63
Q

Viable cell counts:
advantage
disadvantage

A

counts only living cells…but it takes awhile

64
Q

Plate counts:

A

single cell gives rise to colony

65
Q

Turbidity

A

is proportional to concentration of cells…sort of

Measured with spectrophotometer

66
Q

Carbon source distinguishes different groups

A

Heterotrophs use organic carbon

Autotrophs use inorganic carbon as CO2

67
Q

Nitrogen required for

A

amino acids, nucleic acids
Many use ammonia (some convert nitrate to ammonia)
Nitrogen fixation important

68
Q

Thses can either take and make energy or used to make up grow

Know two Precursor- what pathway and what they make

Metabolic pathway

A

slide 31 ppt 4 write it on card

69
Q

Know these and what energy or carbon soure

A

slide 33 ppt4

70
Q

Complex media

Chemically defined media

A 
Complex media (undefined) contains variety of ingredients
Exact composition highly variable
Often an enzymatic digest of proteins
Chemically defined media (synthetic) composed of exact amounts of pure chemicals
71
Q

how will i grow a mesophilic anarode

A

incubator and Anaerobic glove chamber

72
Q

Direct cell counts,

Advantage and disavatage

A

Advantage is its rapid doesn’t cost a lot

Disadvantage- non way to tell if the cell is dead or alive

73
Q

Direct microscope count (Petroff-Hauser slide)

A

Rapid

cost a lot of money

74
Q

Article -

A

n

75
Q

Turbidity is proportional to

?advantages ? and not?

A

concentration of cellsMeasured with spectrophotometer
Have to have match with cell direct cell
Disadvantage to cloudy or to dilute

76
Q

6.1,.2

A

:(

77
Q

why would we want to make shit out od Poly-β-hydroxybutyrate?

A

degrades great alternative to plastic

78
Q

Gas vesicles: controlled

to provide

A

buoyancy

79
Q

Calcium dipicolinate

A

dehydrates cytoplasm about cells

80
Q

Biosafety levels range from BSL-1 - BLS4

A

Biosafety levels range from BSL-1 (microbes not known to cause disease) to BSL-4 (lethal pathogens for which no vaccine or treatment exists)

81
Q

Bacterial endospores:
Mycobacterium species
Pseudomonas species:
Naked viruses

A

Bacterial endospores: only extreme heat or chemicals completely destroys
Protozoan cysts and oocysts: resistant to disinfectants; excreted in feces; causes diarrheal disease if ingested
Mycobacterium species: waxy cell walls makes resistant to many chemical treatments
Pseudomonas species: resistant to and can actually grow in some disinfectants
Naked viruses: lack lipid envelope; more resistant to disinfectants

Micro Bio 2 test (4 decks)

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