Lab Final Review Flashcards
(176 cards)
1
Q
Describe the basic aseptic protocol?
A
-disinfect work area
-sterilize loops and needles before use
-sterilize culture tubes before use
working with agar plates
-final sterilization of loops, needles, and tubes
-disinfect work area
2
Q
List the steps of the plating of microbes
A
- inoculating loop is heated until it is red-hot
- organisms in culture are dispersed by shaking tube
- tube cap is removed and mouth of tube is flamed
- a loopful of organisms is removed from tube
- loop is removed from culture and tube mouth is flamed
- tube cap is returned to tube
3
Q
generation time =
A
2^n
4
Q
Describe the lag phase
A
very little growth few to no living cells
5
Q
Describe the log phase/exponential growth phase
A
lots of binary fission
6
Q
Describe the stationary phase
A
amount of growth=amount of cells dying; slow growth
7
Q
Describe the death phase
A
more cells dying than living cells; due to limiting factors
8
Q
What are the phases of microbial growth in order?
A
- lag phase
- log phase/exponential growth
- stationary phase
- death phase
9
Q
How is microbial growth measured?
A
by serial dilutions
10
Q
What is direct method serial dilutions?
A
counting colonies by hand
11
Q
What is indirect method serial dilutions?
A
spectrometry
12
Q
Absorbance is also referred to as
A
optical density
13
Q
more tubidity/cloudy=
A
more absorbance
14
Q
1 colony forming unit(cfu)=
A
1e9
15
Q
Lower dilutions=
A
higher absorbance=more cells present
16
Q
Higher dilutions=
A
lower absorbance=fewer cells present
17
Q
With growth occurring over time, _______________, but serial dilutions will cause less and less cells
A
absorbance will increase
18
Q
What is the final electron acceptor in aerobic cellular respiration?
A
oxygen
19
Q
Oxygen is the final electron acceptor in
A
aerobic cellular respiration
20
Q
Obligate/strict aerobes
A
require oxygen to grow
21
Q
Microaerophiles
A
lower than atmospheric oxygen at 20%
22
Q
Facultative anaerobes
A
most flexible group
-can grow using oxygen and without oxygen
23
Q
Aerotolerant anaerobes
A
do not require oxygen to grow, but can tolerate it
-use other organic molecules for metabolism
-though oxygen is not detrimental to them
24
Q
Obligate/strict anaerobes
A
will die in the presence of oxygen, uses H2S or iron oxide
25
Psychorophiles
extreme cold, -5-15 celsius
26
Mesophiles
25-45 celsius
27
Thermophiles
heat loving microbes, 45-70 celsius
28
Hyperthermophiles
extreme heat microbes, 75 and above
29
Increase temperature=
denature proteins and lipid break down= no reaction occurring
30
Decrease temperature=
enzyme reactions slow down
31
Decrease temperature=
enzyme reaction slows down
32
Acidophiles
below 7 pH
33
Neutrophiles
7 pH
34
Alkaliphiles
higher than 7 pH
35
Describe a hypotonic solution
fewer solute particles; cell has lots of solutes
-water rushes in
-cells prefer to be in this state
36
Isotonic solution
number of solutes is an equal in and out of cell
-water moves in and out at equal rate
37
Hypertonic solution
lots of solutes outside cell, few solutes in cell
-typical environment microbes die
-water rushes out
-plasma membrane lysis
38
Obligate halophile
requires high salt concentration
39
Halotolerant
slightly salty concentration
40
Osmophile
require high sugar concentration
41
Antimicrobial
chemical agents that halt the growth and/or kill any microorganism
42
Antibiotics
bacteria, living organisms
43
Antivirals
viruses
44
antifungals
fungi
45
Antiparasitics
parasitic animals and protozoans
46
What are the three main targets of antibiotics?
cell wall, DNA/RNA, and protein synthesis
47
Penicillin and bacitracin target
the cell wall
48
fluoroquinolones targets
DNA and RNA
49
Tetracycline, streptocycline, chloramphenicol targets
protein synthesis
50
Describe penicillin
attacks gram positive & negative; specifically the cell wall
51
Describe bacitracin
attacks gram positive only; specifically the cell wall
52
Describe streptomycin
attacks gram positive & gram negative; specifically protein synthesis
53
Describe tetracycline
attacks positive & negative; specifically protein synthesis
54
Describe chloramphenicol
attacks gram negative & positive; specifically protein synthesis
55
Describe fluoroquinolones
attacks gram positive & negative; specifically DNA
56
What is the goal of identifying antibiotic susceptibility with antibiotics disk diffusion
goal is to look for resistance(no growth)
57
Describe antiseptic
inhibit growth and sometimes kill
-gentle on living tissue
58
Describe disinfect
chemical used on nonliving organisms to kill
-kills everything including spores
59
Describe sanitizers
don't completely eliminate microbes
-reduce number down to a safe level as opposed to killing everything
60
Describe bacteriostatic
inhibit growth
61
Describe bactericidal
kill all microbes
62
large zone of inhibition=
better control of bacteria
63
Which API 20E tests are used for carbon utilization?
-acetoin
-amygdalin
-arabinose
-citrate
-glucose
-inositol
-mannitol
-melibiose
-sorbitol
-sucrose
-rhaminose
_________________________
64
Which API 20E tests are used for protein utilization?
-arginine
-lysine
-ornithine
-tryptophane
-gelatin
-indole
65
Which API 20E test is used for nitrogen utilization?
urea
66
(API 20E results)
darker boxes=
higher number=positive result
67
(API 20E results)
lighter boxes=
lower number=negative result
68
(API 20E results)
closer to 100
positive
69
0 means
negative result
70
What are the tests for anaerobic conditions
ADH, LDC, ODC, H2S, URE
71
What are the types of horizontal gene transfers?
1. recombination
2. transformation
3. conjugation
4. transduction
72
Define recombination
breaking the covalent bonds of the DNA strands to insert new DNA and form covalent bonds
73
Cell division for bacteria is known as
Binary fission
74
In this phase, the cells are adjusting to the environment.
Lag phase
75
In this phase, the cells reach the maximum rate of cell division
Log phase
76
In this phase, cells will stop growing or grow very slowly
Stationary phase
77
In this phase, limiting factors intensify becoming detrimental to any cell
growth.
Death phase
78
Generation time should be measured during which phase?
Log phase
79
A dilution of 1:10,000,000 is equivalent to 10 to which exponent?
-7
80
A dilution of 1:1,000,000 is equivalent to 10 to which exponent?
-6
81
When plating out a serial dilution series, which dilution would have the
fewest colony forming units?
1:10,000,000
82
An increase in the optical density or absorbance indicates ______ microbial
organisms
An increase in the number of
83
Bacteria that must grow in oxygen because their metabolism requires oxygen
Obligate aerobes
84
Bacteria that have a flexible metabolism for oxygen conditions
Facultative anaerobes
85
Bacteria that cannot grow in an oxygenated environment
Obligate anaerobes
86
Many bacteria pathogen have an optimal growth between 35ºC and 40ºC are classified as
mesophiles
87
Which bacteria's colonies change color from white (higher temperature) to
red (lower temperature)
Serratia
88
pH refers to what?
The concentration of hydrogen ions
89
A cell that has fewer solutes than its environment is
Hypotonic
90
A cell that has the same solute concentration as its environment is
Isotonic
91
A cell that has more solutes than its environment is
Hypertonic
92
A microbe such as Halobacterium salinarium thrives in high salt
concentration environment is known as a
Obligate halophiles
93
Antimicrobials are compounds that kill or inhibit
Any type of microorganisms
94
Antibiotics are compounds that kill or inhibit
Bacteria
95
Antivirals are compounds that kill or inhibit
Viruses
96
Penicillin targets
The cell wall
97
Bacitracin targets
The cell wall
98
Tetracyclines targets
Protein synthesis
99
Streptomycin targets
Protein synthesis
100
Chloramphenicol targets
Protein synthesis
101
Substances that inhibit or kill microorganisms but are gentle enough to apply
to living tissue are
Antiseptics
102
Chemical agents that are applied to inanimate (non-living) objects to kill
microorganisms are
Disinfectants
103
A substance that has been oxidized has ____ an electron.
Lost
104
Fermentation (anaerobic) is a form of energy metabolism where the final
electron acceptor is
Organic molecule (pyruvate)
105
The API 20 E tests for
Gram negative bacteria
106
The API 20 E tests for bacteria that do
-Oxidation and fermentation
○ No oxidation and fermentation
107
Which test is NOT completed under anaerobic conditions?
-MEL
○ *tests for anaerobic conditions: ADH, LDC, ODC, H2S, URE
108
Which test examines protein utilization?
ADH
109
Which test examines carbon utilization?
SOR
110
Which test examines antibiotic resistance?
ONPG
111
Which test examines aerobic respiration?
H2S
112
Which test examines nitrogen utilization?
URE
113
The E. coli used in this experiment is either resistant to streptomycin or ampicillin.
Which type of plasmid is responsible for this trait?
R plasmid
114
The streptomycin resistance gene is located on
Genome chromosome
115
The ampicillin resistance gene is located on
Plasmid
116
The nalidixic acid resistance gene is located on
Genome chromosome
117
Which resistance gene will be transferred during conjugation?
Ampicillin
118
Which strains will grow on the LB plate?
E. coli (strr)
E. coli (ampr, nalr)
E. coli (strr, ampr) conjugation strain
119
Which strains will grow on the LB + nal plate?
E. coli (ampr, nalr)
120
Which strains will grow on the LB + amp plate?
-E. coli (ampr, nalr)
-E. coli (strr, ampr) conjugation strain
121
Which strains will grow on the LB + str plate?
-E. coli (strr)
-E. coli (strr, ampr) conjugation strain
122
Which strains will grow on the LB + amp + str plate?
E. coli (strr, ampr) conjugation strain
123
In this phase, cells will stop growing or grow very slowly
Stationary phase
124
In this phase, the dead cells take up a larger portion of the culture and little to
no growth occurs.
Death phase
125
How many cells are present after 10 generations (starting from 1 cell) of
exponential growth (2^n)
1024
126
A dilution of 1 ml bacteria from broth into 999 ml broth or water
1/(1+999) = 1:1000
127
A serial dilution of 1:100 follow by 1:100 gives a final dilution of
1:10,000
128
A serial dilution of 1:4 followed by 1:2 gives a final dilution of
1:8
129
A dilution of of 0.1 ml bacteria from broth in 9.9 ml broth or water
1/(0.1+9.9) = 1:10
130
A 1:10,000,000 is a common dilution factor, which serial dilution will end
with this dilution?
1:100,000,000
131
Which generation time is calculated from 15 x log 2 / (log 1257 - log 536)?
1.457
132
Two samples have the following absorbance readings 0.50 (A) and 0.67(B),
which one has more cells present?
B
133
The generation of cellular energy, ATP, can have metabolic reaction that
require a particular amount of which physical property?
Oxygen levels
134
Microbes that require oxygen to grow but at much lower levels than 20% are
microaerophiles
135
When using a fluid thioglycollate media which type of bacteria would be
present at the bottom of the media?
Obligate anaerobes
136
Which bacteria have optimal growth above 75ºC?
hyperthermophiles
137
When the temperature decreases past the optimal, the activity of this
molecule will slow down
Enzyme activity
138
When the temperature increases past the optimal, lipids can be destroyed
affecting which structure?
Phospholipid bilayer (The cell membrane)
139
When the temperature increases past the optimal, the hydrogen bonding in
the RNA breaks down and the proteins denature in this structure.
Ribosomes
140
A bacterium that grows at a pH of 7
neutrophile
141
An environment that has the same amount of solutes as a cell
isotonic
142
These microbes can grow in excessive sugar concentrations
osmophiles
143
Antibiotics are compounds that kill or inhibit
bacteria
144
Bacitracin affects which type of bacterial cells
Gram positive
145
Fluoroquinolones targets
DNA
146
If Escherichia coli has no zone of inhibition to the antibiotic penicillin, the
bacteria is
resistant
147
If Staphylococcus has a zone of inhibition of less than 28 mm to the
antibiotic ampicillin, the bacteria is
resistant
148
If Serratia marcescens has no zone of inhibition to the antibiotic penicillin,
the bacteria is
resistant
149
If Klebsiella has a zone of inhibition of greater than 15 mm to the antibiotic
streptomycin, the bacteria is
sensitive
150
Chemical agents that are applied to inanimate objects to kill microorganisms
are
disinfectant
151
These agents reduce microbial numbers to safe levels but do not eliminate all microbes.
sanitizer
152
Hydrogen peroxide is a(n)
disinfectant
153
A substance that has been reduced has ____ an electron.
gained
154
Anaerobic respiration is a form of energy metabolism where the final
electron acceptor is
Organic or inorganic molecule, NOT oxygen
155
Which test must be completed under anaerobic conditions?
LDC
156
*tests for anaerobic conditions:
ADH, LDC, ODC, H2S, URE
157
Which test examines protein utilization?
IND
158
Which test examines carbon utilization?
GLU
159
Which test examines carbon utilization?
ARA
160
Which test examines nitrogen utilization?
URE
161
These bacteria have on average a negative reaction to the CIT test?
Providencia
162
These bacteria have on average a positive response to the GEL test
Vibrio cholerae
163
These bacteria have on average a positive reaction for all the carbohydrates
but a negative response to the GEL test?
klebsiella
164
This type of mutation changes the DNA and changes the protein by shortening or
truncating it.
Nonsense mutation
165
The synonymous substitution rate is used to determine the mutation rate. Which type of
mutation results in synonymous substitutions?
Silent mutation
166
As the genome size increases, the mutation rate _____.
decreases
167
Horizontal gene transfer create new variation in bacteria through
recombination. Recombination requires the breaking of which type of bonds in the DNA?
covalent bonds
168
This form of bacterial horizontal gene transfer involves naked DNA?
transformation
169
This form of bacterial horizontal gene transfer includes indirect contact between two cells
and only specific genes can be transferred between the cells.
Specialized transduction
170
This form of bacterial horizontal gene transfer typically occurs between bacteria of the
same species or more distantly related?
Transformation
171
This form of bacterial horizontal gene transfer requires a dead bacterial cell that leaves
behind DNA?
Transformation
172
Microbial eukaryotes create variation within a chromosome by which method?
Crossing over
173
This type of mutation changes the DNA and changes the protein by replacing one
amino acid with another.
Missense mutation
174
This form of bacterial horizontal gene transfer requires two living bacterial cells?
conjugation
175
this form of bacterial horizontal gene transfer includes direct contact between two cells.
conjugation
176
