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Microbiology > Chapter 4- Microbial Growth > Flashcards

Chapter 4- Microbial Growth Flashcards

(71 cards)

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1
Q

Nobel Prize for disease causing microbes; developed methods of cultivating bacteria

A

R. Koch

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2
Q

Fannie Hesse suggested AGAR medium to Koch because

A

there were limitations with solidifying liquid media w/ gel media such ass melting @ certain temps AND digestible by bacterias

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3
Q

Microbes can grow in EXTREME conditions such as

A

oceanic, volcanic, polar regions

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4
Q

Why is it important to grow microbes in culture?

A

Each species grow under specific conditions, medical significance, nutritional/ industrial uses

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5
Q

Binary fission

A

replication of parent cell that creates two identical daughter cells that often stick together & form chains, pairs, etc

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6
Q

exponential growth

A

population doubles each division

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7
Q

generational time

A

time it takes for population to double

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8
Q

How do bacteria/prokaryotic cells divide?

A

Binary Fission

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9
Q

Consequences of exponential growth

A

can cause bacteria to spread very rapidly in such short amount of time

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10
Q

Growth can be calculated by

A

Nt= No x 2^N ; N= time incubated/ generation time

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11
Q

Microbes attach to surfaces and live in polymer encased communities called

A

biofilms

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12
Q

examples of biofilm include

A

dental plaque, sink gunk, toilet scum

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13
Q

Most bacterial infections involve

A

Biofilms

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14
Q

Treatment of infections with biofilm are troublesome bc

A

they are often resistant to immune system and antibiotics

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15
Q

How are biofilms helpful?

A

Bioremediation efforts use microbes to degrade harmful chemicals are enhanced by biofilms

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16
Q

population of cells derived from a single cell

A

pure culture

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17
Q

pure cultures can only be obtained via

A

ASEPTIC TECHNIQUE

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18
Q

procedures that help prevent accidental introduction of unwanted microbes

A

aseptic technique

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19
Q

to obtain pure culture, you need

A

culture medium, aseptic technique and method to separate individual cells

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20
Q

If correct conditions are in place while obtaining pure culture then

A

single cell will multiply to form visible colony

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21
Q

*What is used to solidify growth medium and helps prevent bacteria to be destroyed at high temps and digestible?

A

***** Agar **

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22
Q

Method that allows air to enter but excludes contaminants

A

Petri Dish

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23
Q

Method that isolates microbes

A

**Streak method ***

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24
Q

Microorganisms grown on agar plates / in test tube are

A

closed systems/ batch cultures

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25
Nutrients are not renewed/ wastes are not removed
in batch cultures/ closes systems
26
When cells grow in closed system/ batch cultures
population increases in stages and declines
27
growth pattern observed when cells are grown in closed systems
growth curve
28
5 stages of growth curve
Lag Phase, Log Phase, Stationary, Death Phase, Phase of Prolonged decline
29
method used to maintain constant cell growth by continuously adding nutrients and removing waste
Open System/ Continuous Culture
30
of cells don't increase, cells begin synthesizing enzymes required for growth, delay dependent on conditions
Lag Phase
31
Cells divide at constant rate, primary metabolites (amino acids) & secondary metabolites (antibiotics) produced and wastes accumulate
Log (Exponential) Phase
32
Nutrients levels too low to sustain growth
Stationary Phase
33
Total number of viable cells decrease
Death Phase
34
Cells that survive death phase adapt to tolerate worsened conditions (cells can still multiply for a short period of time)
Phase of Prolonged Decline
35
Conditions that contribute to microbial growth
Temperature, Atmosphere, pH, water availability
36
temperature range in which growth occurs
Cardinal temperatures
37
Cardinal temperature ranges
Minimal (lowest growth can occur) Maximal (highest growth can occur) Optimal (growth is most rapid at this temp)
38
Pathogens are mesophiles
Temp requirements are 35-40 celsius
39
Temperature and Food Preservation
Refridgerators stay at 4 C to slow spoiliage by limiting fast growing microbes
40
freezing preserves food but DOES NOT
kill microbes
41
Microorganisms can grow in _________ environments
aerobic or anaerobic
42
Microbes that use molecular oxygen; produces more energy than microbes that dont
Aerobic
43
Microbes that can grow in absence of oxygen
Anaerobic
44
require oxygen for growth/ respiration; bacterial growth @ top of test tube
Obligate aerobes
45
facultative aerobe
do not REQUIRE oxygen for growth, BUT grows better when oxygen present; used oxygen if available for respiration, bacterial growth dispersed within test tube
46
cannot grow w/ oxygen present (lacks enzymes that neutralize harmful toxins of O2); does NOT use oxygen for respiration; bacterial growth
Obligate Anaerobic
47
grows equally well with or w/o oxygen, does not use oxygen for respiration, bacterial growth throughout test tube
Aerotolerant Anaerobe
48
grows only if small amounts of O2 are available; requires o2 for respiration; bacterial growth towards top of test tube
Microaerophile
49
Reactive Oxygen Species (ROS)
harmful by products of O2 respiration (superoxide, hydrogen peroxide) that are toxic to cells
50
bacterias can survives a range of pH; most microbes are ____ & optimum near _____
neutrophiles pH 5-8 ; acidophiles (pH5.5 and below) alkaliphiles (pH 8.5 and higher)
51
HALO
salt
52
ALL micro organisms require _____ for growth
WATER
53
If solute concentration is higher outside of cell than inside, water moves out of cell resulting in
cytoplasm dehydrating and shrink from cell wall (plasmolysis)
54
Process where Water flowing out the cell causing cytoplasm to dehydrate and shrink from the cell wall
Plasmolysis
55
Why is carbon one of the most important requirements for microbial growth?
STructural backbone of all living matter
56
______ use organic carbon; _______ use inorganic carbon
Heterotrophs; Autotrophs
57
What converts inorganic carbon to organic carbon?
Carbon fixation
58
Major Elements that influence Microbial Growth
C, N, P, S, K, Mg, Ca, I
59
Trace Elements that influence Microbial Growth
Co, Zn, Cu, Mo, Mn
60
Many bacteria use nitrogen from the atmosphere via
nitrogen fixation; nitrogen used for synthesizing amino acids
61
This is essential for nucleic acids, phospholipid synthesis, and ATP production
phosphorus
62
compounds that some microbes in growth medium require because it cannot synthesize them
growth factors
63
Microbes growth factor requirements
reflects its biosynthetic capabilities
64
organisms that require growth factors
Fastidious (Ex: Neisseria species)
65
Nutritional factors that effect microbial growth
Sunlight/ Chemical compounds
66
_____- extract energy from sunlight; _______ extract energy from chemicals
Phototrophs; CHemotrophs
67
**** these medias can be used to detect or isolate a species from a mixed population ****
differential & selective
68
determines total number of microorganisms in a sample (both living and dead)
direct cell counts
69
Determine number of cells capable of multiplying
Viable Cell counts
70
Microorganisms often live in a
biofilm
71
Microorganisms grow close in associations containing multiple different species
Activities of one organism often affect growth of another

Microbiology (42 decks)

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