Slide deck 3 Flashcards
(173 cards)
1
Q
What do fimbriae and pili do?
A
attach to surfaces, bacterial conjunction and transformation, and twitching
2
Q
What is the function of flagella?
A
swimming, and swarming motility
3
Q
what is the function of endospore?
A
survival under harsh environmental conditions
4
Q
what are fimbriae and pili?
A
short, thin, hairlike, protein appendages
5
Q
how many fimbriae and poli per cell (approximately)?
A
up to 1000/cell
6
Q
T/F: fimbriae can assist with DNA uptake.
A
true
7
Q
How many sex pili are there per cell?
A
usually only one
8
Q
what do sex pili look like?
A
longer, thicker, less numerous than normal pili (1-10/cell)
9
Q
what genes are in sex pili?
A
genes for formation of plasmids
10
Q
what are pili and fimbriae required for?
A
conjugation
11
Q
What is conjugation?
A
this is where pili and fimbriae make a canal and connect one cell to another, making DNA flow from one to another.
12
Q
where are bacteria generally moving around?
A
usually aquatic environments
13
Q
T/F: bacteria only swim in aquatic environments
A
false
14
Q
how do bacteria move around?
A
using their flagella
15
Q
what are the methods of moving on solid surfaces?
A
swarming, gliding, twitching, and sliding
16
Q
T/F: sliding is a movement
A
false, they are not really moving but just splitting and moving a little as they slip but not technically truely moving
17
Q
How many flagella does one cell have?
A
they can have a ton
18
Q
what are flagella?
A
threadlike, locomotor appendages extending outward from a plasma membrane and cell wall
19
Q
what is the most common way bacteria move?
A
flagella
20
Q
what are the functions of flagella?
A
motility and swarming behaviour, and attachement to surfaces
21
Q
T/F: flagella may be a virulence factor
A
true
22
Q
why are flagella a virulent factor?
A
not necessarily them but it helps harmful bacteria get to host cells.
23
Q
what does monotrichous mean?
A
one flagellum
24
Q
what does polar flagellum mean?
A
one flagellum at each end of the cell
25
what is the name of a cell with two flagellum at each end of the cell?
amphitrichous
26
what does lophotrichous mean?
cluster of flagellum at one or both ends
27
when flagellum spread across the entire surface of a cell what is the name of its pattern?
peritrichous
28
what are bacterial flagella?
thin, rigid protein structures
29
how can you view flagella?
specially stained and under a bright-field microscope
30
how many parts is the flagella composed of?
three
31
what is the flagella filament?
a projection extending from the cell surface to the flagella tip
32
what is the basal body?
a series of rings extending under the outer membrane/peptidoglycan
33
what are the rings of a basal body?
L ring, P ring, MS ring, C ring
34
what does the basal body do?
drive flagellar motor
35
what is the hook of the flagella?
this is the thing linking the filament to the basal body
36
T/F: most harmful bacteria have flagellar motion.
true
37
what are flagella studied alongside of?
sperm tails
38
what is flagellar synthesis (broadly)?
complex process of making the flagella involving many genes/gene products
39
how is flagellar synthesis completed?
new flagellin molecules transported through the hollow filament
40
what is Type-III secretion? Where is it used?
moving a protein up a hollow tube adding more proteins to the end; used during flagellar synthesis
41
what type of protein is used in flagellar synthesis?
flagellin.
42
what aids during self-assembly of flagellar filament subunits? Where is it located?
filament cap at the tip
43
T/F: Archaeal flagella are thicker than bacterial.
false
44
What is the major differences between flagellar synthesis in archaea and bacteria?
archaeal flagella are not hollow meaning they cannot do type III secretion
45
what parts of the archaeal flagella are hard to distinguish?
basal body and the hook
46
T/F: archaeal and bacterial flagella are made of one protein.
false, archaeal are made of more than one but bacterial are made of one
47
What is archaeal flagella more related to than bacterial flagella?
more related to type IV bacterial pili
48
where does growth occur in archaeal flagella? and why?
from base not tip, because they are not hollow
49
Are the archaeal and bacterial S-layers the same?
no, archaeal has a different conformation than bacterial
50
what kind of shape is archaeal flagella?
L like shape extending from the plasma membrane
51
T/F: archaeal flagella have no hook structure.
true, they curve making the L-shape
52
How do flagella help in movement?
they rotate like a propeller
53
how fast can flagella rotate?
1100 rev/sec
54
What direction will a cell move in counterclockwise flagellar motion?
forward
55
How do flagella make a cell move in what pattern?
run-tumble-run-tumble...
56
what does a flagellar tumble mean?
when the flagella moves in a clockwise rotation disrupting the cell.
57
Do all cells (with flagella) have a reverse clockwise gear?
no
58
How do bacteria sense nutrients?
chemoreceptors
59
What is the mechanism of flagellar movement?
2 part motor producing torque
60
What rings interact with a stator?
C ring and MS ring
61
what proteins make up the stator?
Mot A and Mot B proteins
62
what do Mot A and B do?
form a channel through the plasma membrane to allow for rotation
63
where and how do protons help flagellar movement?
Mot A and B channels using energy of proton motive force
64
what is the most primitive way for generating ATP?
the proton pump created by Mot A and Mot B
65
what allows for movement of the proton pump?
charge chain
66
what is chemotaxis?
movement toward a chemical attractant or away from a chemical repellant
67
what is chemorepulsion?
changing concentrations of chemical attractants and chemical repellents binding chemoreceptors of chemosensing systems
68
T/F: behaviour of bacterium is altered by temporal concentration of chemical
true
69
What kind of bacteria are spirochete
gram negative bacteria
70
what are the three layers of spirochetes?
- PF: periplasmic flagella
- PC: protoplasmic cylinder
- OM: Outer membrane
71
where are the flagella contained in spirochetes?
in the periplasma wound around the cell and inside the outer sheath
72
how do spirochetes move?
they flex and spin through aquatic environment
73
T/F: spirochetes have a peptidoglycan.
true
74
How do spirochetes invade host cells?
they swim to them and will adhere to the cell and crawl along the surface
75
what is bacterial swarming?
a collective mode of motion in which cells migrate rapidly over surfaces, forming dynamic patterns of whirls and jets
76
where will bacterial swarming occur?
typically on moist surfaces
77
what is the structure that is typical to swarmer bacteria?
peritrichous flagella
78
In addition to flagellar rotation how do the swarmer cells move across the surface?
this will either be with type IV pili or secreting slime
79
What is twitching?
short, jerky motions that are not smooth or continuous
80
what does twitching involve?
type IV pili and slime on the surface
81
what is gliding?
smooth bacterial cell movements
82
how does pili help gliding and twitching?
they act like a rope on a hook pulling the cell along
83
How does a cell go from vegetative cell to spore?
stress caused by no nutrients or cold temperature or others
84
why would a vegetative cell turn into a spore?
because spores are invulnerable so during stress it is much better for them.
85
what is the differences between vegetative cells and spores?
spores are not capable of reproducing and dormant
they have coat proteins (cot) around the cell and SASPs (ssp) condensing the DNA
86
what must a spore do to reproduce?
turn back into a vegetative cell
87
how does a spore become germinated?
through water, nutrients and warm temperatures
88
why would a spore become germinated?
this reanimates itself and returns to the vegetative state allowing it to divide
89
in what type of bacteria does sporulation occur?
almost exclusively gram positive
90
how long does the entire sporulation cycle take?
over hours
91
how many stages is sporulation?
seven
92
what is the very big difference from sporulation division to mitosis?
there is an unequal division during sporulation
93
What happens during stage 1 of sporulation?
axial filament forms
94
What happens during stage 2 of sporulation?
Septum formation and forespore development
95
What happens during stage 3 of sporulation?
engulfment of forespore
96
What happens during stage 4 of sporulation?
cortex is formed
97
What happens during stage 5 of sporulation?
coat is synthesized
98
What happens during stage 6 of sporulation?
completion of coat synthesis, increase in refractility and heat resistence
99
What happens during stage 7 of sporulation?
lysis of sporangium, endospore liberation
100
what is the structure of an endospore?
exosporium, coat, cortex, and core
101
what is contained in the spore core?
DNA, ribosomes, glycolytic enzymes
102
what type of bacteria has a cytoplasmic membrane in a spore?
gram positive
103
what is a spore wall?
normal peptidoglycan which forms the gram positive cell wall
104
what is the cortex of a spore?
thickest layer of a modified peptidoglycan added as protection
105
what is the modified peptidoglycan in the cortex?
it is less cross-linked
106
what is the second layer of the spore structure?
spore coat: most of the time it is keratin but not always
107
What is the difference between an endospore cytoplasm to a typical cytoplasm?
in a spore the cytoplasm is dehydrated and arid
108
What confers heat resistence in spores?
dipicolinic acid (DPA)
109
what is the complex that surrounds the DNA?
coat formed by DNA small acid-soluble protein (SASP) complexes
110
what do DNA-SASP complexes do?
bind to DNA to protect from UV radiation
111
what is water replaced with in the cell?
CaDPA
112
what is the first step of the formation of a vegetative cell? what happens?
activation through warmth and water
- enhanced permeability
- enhanced gerA experssion
- changes on the germinant receptors (GR)
113
what is the second step of the formation of a vegetative cell? what happens?
commitment:
- germinant binds with germinant receptors
- monovalent ion release and core pH increase
114
what is the third step of the formation of a vegetative cell? what happens?
stage 1 germination
- SpoVA channel opens, CaDPA exits
- CLEs activated
- protein synthesis
115
what is the fourth step of the formation of a vegetative cell? what happens?
stage 2 germination
- cortex hydrolysis
- phase dark
- coat degredation initiated
- transcription
- protease
116
what is the fifth step of the formation of a vegetative cell? what happens?
ripening
- complete coat degredation "burst"
- spore elongation
- SASP degredation
- Metabolism
- macromolecular synthesis
117
what is the sixth step of the formation of a vegetative cell? what happens?
outgrowth
- cell division
- protein secretion
- cell wall modification
118
what is the difference between binary fission and mitosis?
binary fission is separation of the cell not the nucleaus whereas mitosis talks about the division of the nucleus
119
T/F: all bacteria divide by binary fission.
false
120
how do most bacterial and archaeal cells reproduce?
by binary fission
121
what happens prior to division in bacteria and archaea?
segregation of the genome
122
what happens in the early phases of binary fission?
cell growth
123
what happens in the second phase of binary fission?
cell prepares for division by enlarging its cell wall, plasma membrnae, and overall volume
and DNA replication starts
124
what happens in the third phase of binary fission?
the septum begins to grow inward and the chromosomes move to the opposite ends of the cell
125
what happens in the third phase of binary fission?
the septum is synthesized completely through the cell creating two separate cell chambers
126
what happens in the fourth phase of binary fission?
daughter cell divides and separates
127
T/F: all cells separate completely after binary fission.
false, some will remain attached by chains, doublets, and other cellular arrangements
128
What are the two othere methods of bacterial reproduction?
budding: unequal cell division of a new organism
multiple fission: many cells formed by one cell and repeated rounds of DNA replication before cell division
129
What is the first step of cell division in E. coli
initiation mass is reached
130
What is the second step of cell division in E. coli
initiation of replication
- two replication bubbles form at the ORI called replisome
131
What is the third step of cell division in E. coli
the cell elongates as the chromosome replication and partitioning continue
- a septum forms when the z-ring forms
132
What is the fourth step of cell division in E. coli
chromosome separates as septation continues and the cell divides
133
what is a replisome?
group of proteins needed for DNA synthesis
134
DNA replication proceeds in _____ from the origin.
both directions
135
where do the origins of replication move at the end of replication?
to opposite ends of the cell
136
what is ParB?
a protein that regulates chromosome segregation and organization in bacterial cells
137
where does ParB bind?
to the DNA near the origin of replication
138
once ParB is bound to DNA what does the complex activate?
ParA (ATPase)
139
once ParA is activated what happens?
it gains the energy t translocate replicated chromosomes to opposite poles
140
What is septation?
formation of cross wall between two daughter cells
141
when does a septum form?
when the Z ring forms
142
what is the Z ring?
this is a structure that forms at the site of cell division made from Fts Z protein
143
where does the Z ring need to be formed in the cell?
in the middle
144
what is the protein FtsZ?
tubulin homologue found in most bacteria and archaea
145
what forms the Z ring (not the protein, the process)?
polymerization via filaments of meshwork
146
what forces the Z ring to the cell centre?
MinCDE system
147
what do MinD and MinE do?
oscillate from one side of the cell to the other
148
in high concentrations of MinC what occurs? where will they be congregating?
repulsion of MinE, at each opposite sides of the cell
149
What is the name of the cell-wall synthesizing machinery?
FtsZ subunit
150
what happens when the divisome is formed?
constriction of the Z ring, invagination of the plasma membran and synthesis of septal wall complete division
151
what is the first step of cell wall synthesis?
peptidoglycan synthesis begins at the cytoplasm with the attachment of uridine diphosphate to the sugar N-acetylglucosamine
152
what is the second step of cell wall synthesis?
NAM binds to bactoprenol
153
what is the third step of cell wall synthesis?
bactoprenol flips
154
what is the fourth step of cell wall synthesis?
autolysins cleave peptidoglycan
155
what is the fifth step of cell wall synthesis?
transclycolases catalyze
156
what is the sizth step of cell wall synthesis?
transpeptidases re-form peptide bridges
157
what determines the site of cell wall growth?
FtsZ
158
in cocci divisomes where does the peptidoglycan form?
at the septum
159
T/F: rods and cocci have the same cell wall growth
false, rods are similar but elongate prior to separation
160
what determines cell diameter and elongation as Z ring forms in rods?
MreB
161
An increase in cellular constituents result in what?
- increase in cell number
- increase in cell size
162
What are the five phases of microbial growth?
1. lag phase
2. exponential phase
3. stationary phase
4. death phase
5. long-term stationary phase
163
during the lag phase, what occurs?
replenishing of spent materials, adapting to a new medium or other conditions
164
during the exponential phase, what occurs?
aka log phase,
rate of growth and division is constant and maximal
165
during which microbial growth phase is population uniform in terms of chemical and physical properties
exponential phase
166
abundance of nutrients helps how (in terms of microbial growth)?
allows transport mechanisms to be saturated so growth increase is minimal
167
T/F: no matter what you do with the environment, there will always be an upper growth limit.
true
168
what are the possible reasons for the stationary phase?
- nutrient limitation
- limited oxygen availability
- toxic waste accumulation
- critical population density reached
169
what is the stationary phase?
growth is ceased and total number of viable cells remains constant
170
what is the death phase?
number of viable cells declines exponentially with cells dying at a constant rate
171
T/F: all bacteria die during the death phase.
false, adaptations can occur
172
what is the long-term stationary phase?
bacterial population continually mutates creating waves of genetically distinct bacterial varients.
173
