Unt 2: Chapter 7: Bacterial and Archaeal Growth Flashcards
1
Q
Most bacterial and archaeal cells reproduce by
A
Binary Fission
2
Q
Some bacteria reproduce by __________ or __________
A
Budding; multiple fission
3
Q
The _______ is formation of a new cell
A
Cell Cycle
4
Q
The 3 phases of the Cell Cycle are
A
- Cell Growth
- Chromosome replicatoin
- Cytokinesis
5
Q
This phase of the cell cycle involves doubling the cell masas
A
Cell growth
6
Q
THis phase of the Cell Cycle involves doubling the genetic material
A
Chromosome replication
7
Q
This phase of the Cell cycle involves physical separation of the cell
A
Cytokinesis
8
Q
Most bacteria have a _____ chromosome
A
singular, circular
9
Q
Where replication begins
A
origin of replication
10
Q
Where replicaiton is terminated, located opposite of the origin
A
Terminus
11
Q
The DNA synthesis machinery
A
Replisome
12
Q
The three components of Chromosome Partitioning
A
ParA protein
ParB protein
parS region on Chromosome
13
Q
The formation of two daughter cells following cell division
A
Cytokinesis
14
Q
Formation of cross wall between two daughter cells
A
Septation
15
Q
1st Step of Septation
A
Selecton of site for septum formation
16
Q
2nd Step of Septation
A
Assembly of Z-Ring composed of protein FtsZ
17
Q
3rd step of septation
A
Assembly of cell wall-synthesizing machineryu
18
Q
4th step of septation
A
Constriction of cell + septum formation
19
Q
After a cell is born, it enters _____ phase
A
growth
20
Q
Cell shape is predetermined by _____
A
genetics
21
Q
In peptidoglycan synthesis, _________ is synthesized from the cytoplasmic side
A
Monomer, (NAG-NAM-pentapeptide)
22
Q
________ is flipped by MurJ flippase in peptidoglycan synthesis
A
Monomer
23
Q
In peptidoglycan synthesis, polymerization happens by _
A
glycosyltransferase
24
Q
___________ interlocks between NAMs
A
Transpeptidase
25
Peptidoglycan formed at central septum
Coccus
26
Elongasome creates
Bacillus
27
Growth occurs in numerous bands around cell, not at the poles
Elongasome, Bacillus
28
Crescentin localizes to one side of the cell
Vibroid
29
Archaeal Cell Cycle
G1 - S - G2 - Segregation of Chromosomes - Cytokinesis
30
Archaeal Cytokinesis is similar to
Eukaryotic cleabage furrow formation
31
Binds the membrane and forms a non-contractile ring at midcell
CdvA
32
Ring constricts to separate the daughter cells
CdvB
33
Recruited with CdvB to the site of division
CdvC
34
Z-ring associated with the new S-layer
FtsZ
35
SegA is similar in strucutre and function to
ParA
36
Structurally unique, but functionally similar to ParB
SegB
37
Observed when microorganisms are cultivated in liquid
Microbial Growth Curve
38
Closed System
Batch Culture
39
Usually plotted as logarith of cell number vs time
Microbial Growth Curve
40
First phase of Microbial Growth
Lag Phase
41
Cell synthesizing new components to adapt to new medium or other conditions in mcirobial growth
Lag Phase
42
2nd Phase of Microbial Growth
Exponential/Log Phase
43
In Microbial Growth this phase is characterized by a rate of growth and dividion which is constant and maximal
Exponential/Log Phase
44
In C. crescetus _____ sites are close together near origin of replication
parS
45
these sites direct the separation of the double strands at origion or replicatoin in chromosome partitioning
parS
46
in chromosome partitioning of C. Crescentus, these proteins bind to the ParS site and nearby
ParB proteins
47
In chromosome partitioning of C. crescentus, ___ guides partitition complex to the opposite pole
ParA
48
In Microbial Growth this phase is characterized by the population being the most uniform
Exponential/Log Phase
49
The concentration of nutrients determines ?
growth rate total cell number
50
The 3rd phase of Microbial Growth
Stationary Phase
51
In Microbial Growth this phase is characterized by in a closed system, eventual growth ceasing
Stationary Phase
52
In Microbial Growth this phase is characterized by the total number of viable cells remaining constant
Stationary Phase
53
Reasons for the stationary phase:
Nutrient Limitation
Limited Oxygen Availability
Toxic Waste Accumulation
Critical Population Density Reached
54
4th phase of microbial growth
Death Phase
55
In Microbial Growth this phase is characterized by the number of viable cells declining and dying at a constant rate
Death phase
56
In Microbial Growth this phase is characterized by nutrient depriviation and the buildup of toxic wastes
Death Phase
57
The 5th phase of microbial growth
Long-Term Stationary Phase
58
In Microbial Growth this phase is characterized by the bacterial population continually evolving or adapting
Long-Term Stationary
59
In Microbial Growth this phase is explained by emergence of genetically distinc variants or natural selection
Long-Term Stationary
60
Phases of Microbial Growth
1. Lag Phase
2. Log/Exponential Phase
3. Stationary Phase
4. Death Phase
5. Long-Term Stationary Phase
61
The time required for the population to double in size
Generation (doubling) time
62
This varies depending on species of microbe and environment
Generation doubling time
63
Growth Rate for binary fission
Nt = N0 x 2^n
64
In growth rate, N0 =
The intitial population number
65
In Growth Rate, Nt=
the population at time t
66
In growth rate, n =
the number of generations in time t
67
Grow under harsh conditions that would kill most other organisms
Extremophiles
68
Lower solute concentration outside the cell than inside the cell
Hypotonic
69
Water enters the cell and may burst
Hypotonic SolutionH
70
Higher solute concentration outside the cell than inside the cell
Hypertonic
71
Water leaves the cell + membrane shrinks
Hypertonic
72
Most microbes live in a _____ environment
Hypotonic
73
In a hypotonic environment microbes are protected by what
cell wall
74
In a hypotonic environment, protists use
contractile vacuoles to expel excess eater
75
_____ channels in the plasma membrane allow solutes to pass
Mechanosensitive (MS)
76
Require NaCl at a concetration above .2M
Halophiles
77
Extreme halophiles require salt concentrations between'
3 M and 6.2M
78
Salt in Systems accumulate what in where
accumulate K and Cl in cytoplasm
79
Why do proteins benefit from Salt-in systems
They need the high salt levels
79
What benefits from salt-in systems?
Proteins
80
Salt-out systems synthesize __________ that do not interfere with growth
Compatible solutes
81
The degree of water availability in percent
Water activity (aw)
82
Low water activity means most water is ____ and
bound; unavailable to microbes
83
Most microorganisms grow well at aw of
.98
84
Microbes that can grow over wide ranges of water activity
Osmotolerant
85
Microbes that grow in a dry condition
Xerotolerant
86
microbes which grow best between pH 0 and 5.5
Acidophiles
87
Microbes which grow best between pH 8 and 11.5
Alkaliphiles
88
Most bacteria and protists are
neutrophils
89
Most fungi prefer (acidic/basic) surroundings
Acidic
90
Microorganisms respont to (internal/external) pH changes using mechanisms that maintain a ____ cytoplasmic pH
external; neutral
91
Exhange potassium for protons
Nuetrophiles
92
Pump protons (H+) out of the cell
Acidophiles
93
Exchange internal Na+ ions for external protons
Alkaliphiles
94
Below optimum temperature enzyme (is/is not) catalytic
is
95
High temperatures may inhibit ______ and be lethal
enzyme functioning
96
There are 3 Cardinal Temperatures
1. Minumum
2. Maximum
3. Optimal
97
These microbes have a temperature range of 0 - 20 C
Psychrophiles
98
Psychorphiles have an optimal temp growth of
15C
99
Psychrophiles have a temp range for growth of
0-20C
100
These microbes have a temperature range of 0-35C
Psychrotrophs/psychrotolerant
101
Psychro-(trophs, tolerants) have a temp range of
0-35C
102
These microbes have a temperature range of 20-45C
Mesophiles
103
The optimal temp for growth of mesophiles is
37C
104
The temp growth range for mesophiles is
20-40C
105
These microbes have a temperature range of 45-85C
thermophiles
106
The optimal temp for growth in thermophiles is
50C
107
The temp range for growth of thermophiles is
45-85C
108
These microbes have a temperature range of 85-100C
hyperthermophiles
109
The temp range for growth of hyperthermophiles is
85-100C
110
What are the benefits of stabilization of proetin structure in thermophiles?
More H Bonds
More proline --> less flexible peptides
Chaperones aid in folding
111
What are the benefits of stabilization of membrane in thermophiles?
More saturated, branched and higher molecular weight
Ether linkages resistant to hydrolysis
112
What are the adaptations of thermophiles
Stabilization of protein structure
Stabilization of membrane
113
This microbe requires O2
obligate aerobe
114
This microbe is usually killed in prescence of O2
obligate anaerobe
115
This microbe requires 2-10% o2
microaerophile
116
This microbe doesn't require O2 but grows better in its prescence
Facultative anaerobe
117
This microbe grows with or without O2
Aerotolerant anaerobe
118
ROS stands for
Reactive Oxygen Species
119
Aerobes produce 3 protective enzymes to protect from ROS
Superoxide Dismutase (SOD)
Catalase
Peroxidase
120
These microbes are adversely affected by increased pressure, but not as severly as nontolerant organisms
Barotolerant
121
These microbes require high pressure for growth
Barophilic/Peizophilic
122
These microbes change membrane fatty acids to adapt to increased pressure
Baro/Peizophilic
123
How do lipids change in barophilic microbes to adapt to increased pressure?
They become unsaturated and shorter
124
What are the ionizing radiations?
X-rays + gamma rays
125
What are the effects of ionizing radiation?
Mutations
Disrupts the chemical structure of many molecules
126
What are extremely resistant to ionizing radiation?
Bacterial Endospores
Deinococcus Radiodurans
127
Most lethal wavelength (260nm)
UV radiation
128
why is 260nM the most lethal wavelength?
It's absorbed by DNA
129
At high intensities, visible light generates what?
1 O2
130
What is 1 O2?
a powerful oxidizing agent
131
What pigments protect light exposed microbes from photoxidatoin?
Carotenoid pigments
132
What are the adaptations of microbes to harsh environments?
Morphological changes (endospore formation)
Growth arrest (entering stationary phase)
Using cellular components as nutrients
Transient Status
Peristers
133
Adaptation of microbes to harsh environments which live/survive in the presence of antibiotics?
Persisters
134
The complex, slime enclosed communites of microbes
biofilm
135
Formation of Extracellular Polymeric Substances
Microbes reversibly attach to conditioned surface and release polysaccharides, proteins and DNA
136
5 Steps of Biofilm Formation
1. Initial Attachment/deposition
2. Irreversible attachment/ adsorption
3. Maturation I / Replication + Growth
4. Maturation II/ Polysaccharide Production
5. Dispersion / Sloughing
137
Heterogeneity in biofilms comes from
differnet microbes
various metabolites
138
What protects microbes from UV?
EPS
139
Emergent Properties of Biofilm
1. Antibiotic treatment failure, when formed on meidcal devises
2. Contaminatoin of drinking water system
3. sewer line clogging
4. wound healing delay
140
Autoinducers in Quorum Sensing Process
N-acylhomoserine lactone (AHL)
Autoinducing peptides (AIPs)
141
Process of Cell-Cell communication that allows bacteria to share information about cell density and adjust gene expression accordingly
Quorum sensing
142
Nromally, AHL diffused (in/out) from cytoplasm to outside
out
143
When cell population is high, AHL diffuses (in/out) the cell which induces specific gene expression
in
144
Mixture of nutrients and other compounds which must contain all growth factors microorganism requires
Culture Medium
145
Classification of Media
1. Chemical Composition
2. Physical Nature
3. Functoin
146
2 ways media can be classified by chemical composition
Defined/synthetic medium
complex media
147
each ingredient can be defined with a chemical formula
Defined/synthetic medium
148
contains some ingredients of nonspeicifc chemical composition
Complex media
149
Examples of Defined/Synthetic Medium
McConkey Agar
Snyder Agar
150
Exampled of Complex Media
Trypticase Soy Agar
Blood Agar
Brain Heart infusion
151
Solidifying agent which most microbes can't degrade and is solid in room temp and liquid around 70C
Agar
152
Partial proteolytic digestion of protein sources
Peptones
153
4 Types of Classification based on Functions
1. Supportive media
2. Enriched media
3. selective media
4. differential meida
154
This media sustains growth of many microorganisms
Supportive
155
Examples of supportive media
tryptic soy broth and agar
156
This media is a supportive media supplemented with special nutrients
Enriched media
157
Example of enriched meida
blood agar
158
This media allows the growth of particular microbes, while inhibiting the growth of others
Selective media
159
Bile salt agar: Select Gram-Negatve bacteria agains Gram Positive bacteria is an example of
Selective Media
160
This media distinguishes among differnt groups of microbes
Differential meida
161
Blood agar: hemolytic bacteria is an example of ____ media
differential
162
3 Classifications of Media Based on Physical State
1. Solid media
2. Semisolid media
3. liquid media
163
This media provides a firm surface where cells can grow. It's used for isolation of colonies for subsequent test
Solid media
164
This media provides a clot-like consistency and is used for motility test or physiological characteristics
Semisolid meida
165
This media is a water-based solution; it flows freely when the container is tilted and growth is observed throhgout the container
liquid media
166
What devices are used to grow microbes without O2?
Anearobic chamber
Candle Jar
167
This allows to select a single bacterial type from a mixed sample
Pure culture
168
This uses enrichment culture technique and streak plate or spread plate methods
Pure culture
169
Encourages growth of microbes with a particular characteristic, while inhibiting growth of others
Enrichment culture
170
Three factors to be considered when isolating pure cultures
1. Suitable source of microbes
2. Nutrients that should and shouldn't be included in the medium
3. Environmental conditions
171
Used to obtain individual cells that are separated from each other
Streak plate
172
Spread a mixture of cells on an agar surface using an inoculatng loop or sqab
Streak plate
173
Group of bacteria derived from the same mother cell
Colony
174
Small volume of diluted sample is transferred to the center of an agar plate and spread evenly over surface
Spread plate
175
Dilution in spread plates are made by
serial dilution
176
Sample is serially diluted and mixed with melted agar
Pour Plate
177
Use miniature cultures and incubate in many different conditions to find the best one
culturomics
178
Bring natural environment into the lab, diffuses nutrients but retains microbes, and dilution can contain a single cell
diffusion chamber
179
Growth on animals or tissues in lab
Co-culturing
180
Direct measurements of cell number
Direct Counts
181
3 types of direct counts
1. counting chambers
2. membrane filter method
3. electronic counters - flowcytomery, coulter counter
182
Indirect measurement of amount of microbes
indirect counts
183
3 types of indirect counts
1. metabolic activity
2. dry weigth
3. turbidity
184
number of microbes calculated from chamber's volume and dilutions
Counting Chambers
185
Advantages: easy, inexpensive and relatively quick
Gives infromation abotu size and morphology of microbe
Counting Chamber
186
Disadvantage: population must be large and evenly dispersed
Counting Chamber
187
Bacteria from aquatic samples are trapped on membranes which are soaked in culture media. Colonies thn grow on membrane and colony count determines number of bacteria in sample
Membrane Filter Method
188
Microbial suspension forced through small orifice with a laser light beam
Electronic Counter - Flow Cytometry
189
Cells of differing size, internal complexity and other characteristics within a population can be counted
Electronic Counter - Flow Cytometry
190
Microbial supsension forced through a small hole. Electrical current flows through hole, electrodes on both sides measue the size of the cell which is interpreted from the change of resistance
Electronic Counters - COulter Counter
191
Number of organisms are determined by counting the number of colonies and multiplied by the dilution factor
Dilute + pour plate techniques
192
Results expressed as Colony forming units (CFU)
dilute and pour plate techniques
193
Cells from liquid culture are pelleted and weighed. Time consuming and not very sensitive.
Dry weight
194
Measured by using spectrophotometer
Turbidity
195
Measure changes in nutirents, gas, ATP, and pH
metabolic activities
196
An open system which maintains cells in a maximum growth rate for extended periods
Continous culture system
197
Advantages: allow study of microbial growth at low nutrient level, close to those to natural environment, useful in microbial ecology
Continuous culture system
198
Advantages of Continuous Culture System
allow study of microbial growth at low nutrient level,
close to those to natural environment,
useful in microbial ecology
199
Regulating factor is a nutrient present in limiting quantities which a constant dilution rate. It operates best at lower dilution rates
Chemostat
200
Regulating factor is turbitiy of the medium monitored by photoelectirc cell. Dilution rate varies, and operates best at high dilution rates
Turbidostat
201
ROS which cause death
Superoxide radical
Hydrogen peroxide
Hydroxyl radical
