L6 Flashcards

(96 cards)

1
Q

an aggregation of cells arising from a single parent cell

A

colony

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2
Q

requirements for growth include the nutrients:

A

C, O, H, N

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3
Q

What purposes does carbon serve in terms of chemicals?

A

needed for structural backbones of chemicals

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4
Q

What is nitrogen needed to form?

A

amino acids

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5
Q

What is sulfur used in?

A

sulfur-containing amino acids

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6
Q

What is phosphorous used in?

A

for cell membranes and nucleic acid synthesis

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7
Q

name three trace elements

A

Cu, An, Mb, and Zn

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8
Q

describe the process of nitrogen fixation

A

reduce nitrogen gas as N2 to ammonia (NH3-), provide usable nitrogen to other organisms

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9
Q

What 4 elements make up 95% of cells?

A

C, O, H, N

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10
Q

define organic growth factors

A

essential organic compounds an organism is unable to synthesize and must get from environment

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11
Q

This uses light energy, and catabolizes organic compounds for nutrients:

A

photoheterotroph

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12
Q

This uses organic compounds for energy and carbon:

A

chemoheterotroph

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13
Q

Uses inorganic carbon sources such as carbon dioxide:

A

autotroph

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14
Q

Uses light as an energy source:

A

phototroph

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15
Q

Catabolizes organic molecules from other organisms:

A

heterotroph

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16
Q

Uses redox reactions of organic/inorganic compounds as energy source:

A

chemotroph

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17
Q

Uses light energy and carbon dioxide for carbon :

A

photoautotroph

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18
Q

Uses carbon dioxide for carbon, catabolizes organic compounds for nutrient:

A

chemoautotroph

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19
Q

Acquires electrons from same organic molecule that provides carbon and energy:

A

organotroph

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20
Q

Acquires electrons from an inorganic source (H2NO2-, H2S, etc.)

A

lithotroph

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21
Q

Consumes dead matter, are heterotrophs:

A

saprophytes

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22
Q

What is the difference between obligate aerobes and anaerobes?

A

ob. aerobes: oxygen is essential, acts as final electron receptor
ob. anaerobes: oxygen is deadly for these organisms

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23
Q

What type of organism requires oxygen levels at 2-10%? Give an example of one.

A

microphiles/microaerophiles; H. pylori

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24
Q

define facultative anaerobes

A

can do fermentation or anaerobic metabolism; less metabolic efficiency without oxygen

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25
How do aerotolerant anaerobes tolerate oxygen?
because they have enzymes to handle the toxic forms of oxygen
26
What effect does temperature have?
has effect on 3D structure of protein and lipid components
27
What's the difference between minimum growth temperature and maximum growth?
lowest temp. metabolism is possible vs vs. highest temp. metabolism possible
28
What is the temperature where metabolism is highest?
optimum
29
What temperatures do the following grow at: Psychrophile, Psychortrophs, and Mesophile?
below 15 degrees C; at 0 degrees C, usually no higher than 4 degrees C; 20-40 degrees C
30
What type of medophile can survive brief periods of higher temperatures?
thermoduric organisms
31
What type of organisms might you find in composts and hotsprings?
thermophile
32
What type of organism thrive above 80 degrees C? What's an example of one that can survive an hour in the autoclave at 121 degrees C?
hyperthermophile
33
What does pH interfere with?
bonding
34
Give an example of an acidophile and an alkalinophile.
acido: H. pylori alka: Vibrio cholerae
35
What is the optimum pH for a neutrophile?
6.5-7.5
36
define osmotic pressure
pressure exerted on semipermeable membrane
37
What causes a cytoplasm to shrivel? What's the term for it?
loss of water; plasmolysis
38
What is unique about obligate halophiles?
adapted to grow under high osmotic pressure such as in the great Salt Lake, some tolerate up to 30 % salt
39
How much salt can facultative halophiles tolerate?
up to 2%
40
What type of pressure do barophiles live in? How much does pressure increase in water per 10M of depth?
under extreme pressure; pressure increases 1 atm. per 10 M depth increase
41
define ecology
live in association with other organisms
42
What are biofilms? Give an example of where you would find one in/on the human body?
different species that attach as a group and display metabolic and structural traits different than expressed by these organisms alone; on teeth
43
What is the term that describes how bacteria are able to respond to nearby bacteria? What does it influence?
Quorom sensing; can influence ability to cause disease
44
liquid media
broth
45
collection of nutrients to allow organisms to grow
medium
46
microorganisms that grow from an inoculum
culture
47
cultures visible on surface of solid medium, we describe colony appearance by shape, margin, elevation, size, texture, appearance, pigmentation, optical property
colonies
48
a sample of a culture
inoculum
49
A clinical specimen uses a sample of human material examined for the presence of:
microbes
50
What sources would you use for an environmental specimen?
ponds, streams, soil or air
51
In a pure culture, cells arise from?
a single progenitor
52
define CFU
(colony forming units), single cell or group of related cells that generate a colony
53
What are isolated colonies?
separate and distinct from all other colonies
54
For something to be sterile it needs to be?
free of microbial contaminants
55
What is the term use to describe the period of time organisms are allowed to grow?
incubation
56
What is the difference between streak plates and pour plates?
streak: sterile inoculating loop used to spread inoculate over medium to separate organisms to isolate CFUs pour: CFUs separated by using a series of dilutions that are mixed and poured in petri dishes
57
What can you use to pick up large organisms with?
micropipette
58
What are petri plates filled with?
warm agar 7
59
What is the purpose of slant tubes? What do they allow to grow?
agar solidifies at an angle; allow larger growing surface while the bottom is almost anaerobic
60
If exact chemical composition is known, it is said to be:
chemically defined media
61
What type of media uses yeast/beef/soy or other proteins?
complex media
62
What does the term "selective" mean when referring to media?
favor the growth of some organisms and inhibits the growth of others
63
What is the purpose of differential media?
presence of a visible change in media or colonies to differentiate types of growing bacteria
64
If the media is said to be anaerobic, what type of organisms will you grow with it?
can use stab cultures to get anaerobic portion of media
65
What compounds are found in reducing media?
compounds like sodium thioglycolate that combines with oxygen to make it anaerobic
66
What is transport media designed to do?
used to carry clinical specimens, designed to maintain ratios of organisms, particularly in stool
67
What form of media is used to differentiate ability to do hemolysis of RBCs?
blood agar
68
What media is used to identify fermentation/fermenters? What color are the non-fermenters?
MacConkey agar; colorless/transparent
69
What two types of animal cells are mostly used in media for organisms requiring living cells?
rabbit, bird
70
What does a carbon dioxide incubator mimic?
GI tract
71
Which organisms grow best with high CO2 and low O2? Give an example.
capnophiles; Neisseria gonorrheae
72
If you are using enrichment culture, what are you trying to do?
use selective media and designed to increase a small number of a chosen microbe to an observable level
73
What would you use for a cold tolerant species?
refrigerator
74
When preserving a culture, how long can you freeze for and still restore?
-50 to -95 degrees C
75
What is lyophilization?
form of preserving culture: freeze dry in a vacuum to remove water, can last decades, revived by adding to liquid culture media
76
define binary fission
divide to produce to = size daughter cells
77
What is budding?
forms a small initial outgrowth that enlarges and then separates
78
Logarithmic/exponential grown describes something that:
grows much faster than arithmetic growth, 2 > 4 > 8 > 16...
79
What is the generation time for most bacteria?
1-3 hours
80
How many phases of microbial growth?
4
81
What is a growth curve?
plots number of organisms in a growing population over time
82
Which phase do you see rapid growth and reproduction?
log phase
83
Which phase do you see cells adjusting to new environment and not reproducing?
lag phase
84
What are the characteristics of the stationary phase?
of dying cells = # being produced, metabolic rate of survivors decreases, can use chemostat
85
What does a chemostat do?
culture device that continually adds fresh medium equal to the amount removed to maintain a culture in a particular phase (typically log and postpone stationary phase)
86
In which phase do more cells die than are produced?
death phase
87
What is flow cytometry used for?
uses light transmission to detect and measure physical and chemical characteristics of cells
88
What is an electronic counter used for?
counts cells as interrupt electric current glowing across narrow tube
89
Describe the 3 steps of the microscopic count.
1) sample placed in cell counter 2) glass slide with a grid 3) count # of bacteria in several squares to estimate bacteria per mL (cc)
90
define membrane filtration
large sample poured through a membrane and then transferred onto solid medium; # of colonies = CFU in original large sample used when organisms are very dilute, at least 100 ml of water collected and passed through filter and transferred to a petri dish with nutrient medium
91
How many CFUs should be plated for a viable plate count?
25-250
92
define MPN
most probably number: statistical estimate, based on the more bacteria in a sample, the more dilutions required to reduce # to zero
93
What device is used to determine turbidity?
spectrophotometer
94
What is the term that describes the rate at which populations utilize nutrients and produce waste?
metabolic activity
95
With dry weight, organisms are:
filtered, dried and weighed
96
Using the genetic method, what did one study estimate regarding 1 gram of garden soil?
100 billion bacteria and archae of 10 million different species