exam 2 Flashcards
(217 cards)
1
Q
what is cellular growth
A
individual cell is getting larger in preparation for replication
2
Q
how to prokaryotes divide
A
binary division
3
Q
how to eukaryotes divide
A
mitosis
4
Q
in chemotaxis, how will a bacteria respond to no attractant or repellent
A
random run and tumble movement
5
Q
in chemotaxis how will a bacteria respond to an attractant or repellent
A
directed movement
6
Q
what type of gradient do bacteria sense
A
sense temporal NOT spatial
7
Q
what happens to a bacterial cell if MCP binds a repellent
A
a signal will be sent to the cell to increase the amount of tumbling
8
Q
if a repellent is present what happens to the rate of CheA autophosphorylation
A
if repellent, increases
9
Q
if a repellent is present what happens to CheY
A
will be made faster
10
Q
if a repellent is present what happens to CheY-P
A
will increase
11
Q
if a repellent is present what happens to CheB
A
will increase
12
Q
what is an adaptation circuit
A
gradient increases or decreases with time and tries constantly to bring gradient back to default
13
Q
doing what changes the way MCP acts towards repellents or attractants
A
adding or removing methyl groups
14
Q
what is the function of CheB-P
A
its a demethylase that removes methyl groups from MCP’s
15
Q
what is the function of Che-R
A
its a methylase that adds methyl groups to MCP
16
Q
what compound of MCP increases tumbling
A
CheY-P
17
Q
what compound of MCP decreases methylation
A
CheB-P
18
Q
what happens to methylation when there is a repellent present
A
methylation is decreased leading to decreased sensitivity of presence of repellent
19
Q
what is the main function of MCP
A
determining if something is a repellent or an attractant
20
Q
what is the function of CheZ
A
removes P from CheY-P
21
Q
what is the function of CheW
A
helps CheA attach to MCP
22
Q
what is CheA
A
accessory protein able to autophosphorylate (pull P off ATP and use P)
23
Q
what compound interacts with Fli proteins in flagella to determine flagellar movement
A
CheY-P
24
Q
what does MCP stand for
A
methyl accepting chemotaxis protein
25
how many methyl groups can generally be added to MCP
around 6
26
how can you modify an MCP transducer
by adding or removing methyl groups
27
what compounds are involved in the adaptation (transducer) circuit
CheR, CheA, CheW, CheB
28
what compounds are involved in the response circuit
CheA, CheW, CheY, CheZ
29
what is the purpose of having a transducer and a response circuit
they sense change in concentration over time and react to the change over time
30
with an attractant how does CheA respond
autophosphorylation decreases
31
with an attractant how does CheY-P respond
increases, increases tumbling
32
with an attractant how does CheB-P respond
increases, decreasing methylation
33
with an attractant increased methylation occurs leading to _____ sensitivity of MCP
decreased sensitivity
34
if the cell moves towards the stimulus ____ sensitivity
decreased
35
if the cell moves away from the stimulus ___ sensitivity
increased
36
what is the function of septum formation in a cell
its the physical division of the cell
37
what must occur first before the cell can properly divide
it must replicate its DNA
38
what are fimbrae
shorter and more numerous than flagella or pili and are thought to be involved in attachment to surfaces/other cells
39
what are pili
one to a few per cell, hollow tube made of pilin involved in attachment and/or conjugation
40
how did griffith show the prevention of phagocytosis
inject pneumonia to mice with capsule they die, inject the same thing but without a capsule into mice and they live
41
what are the types of glycocalyx
capsules and slime layers
42
how can you tell the difference between a capsule and a slime layer
by the degree of organization and the tightness of attachment to the cell
43
is a glycocalyx hydophilic or hydrophobic
hydrophilic
44
what makes up a glycocalyx
polysaccharides and/or polypeptides
45
what is the function of a glycocalyx
attaches cells to surfaces, prevents phagocytosis, prevents desiccation
46
what does glycocalyx literally mean
sugar crown, glycocalyx surrounds the cell in a sugar coating
47
what types of bacteria can produce endospores
a very restricted number of gram positive bacteria (ex. bacillus)
48
what is an endospore
for survival, NOT for reproduction. essentially and extra outer coat to protect
49
what do endospores contain
dipicolinic acid and calcium ion accumulation (these help in resistance)
50
explain the process of sporulation
vegetative cell DNA becomes more dense and lines up, plasma membrane surrounds replicated DNA, spore septum surrounds the isoated portion making a forespore, peptidoglycan forms between membranes, spore coat forms, endospore is released from cell
51
what is the function of the last steps of sporulation
they make the spore resistant
52
what is the function of calcium dipicolinate in an endospore
helps to old strands of DNA together and protects against heat denaturization
dehydrates the spore helps with chemical resistance since all the water is used up, prevents formation of things like H2O2
53
what are the two possible meanings of growth
cell growth or population growth
54
what are the basic requirements for any type of cell division
replication of DNA, partitioning of DNA, septum formation
55
describe in brief the process of binary fission
DNA replication, cell elongation, septum formation, formation of distinct walls, cell separation
56
whats different about the cytoskeleton of eukaryotes versus prokaryotes
prok do not have a cytoskeleton
57
what is the function of a divisome in prok
body involved in division of cell membrane and cytoplasm
58
what is the most common type of prokaryotic motility
flagella
59
what type of prokaryotes typically use an endoflagella
spirochetes
60
what are the types of taxis
chemotaxis, phototaxis, aerotaxis, osmotaxis
61
what kind of motility is not done within fluid environment
gliding motility
62
what is motility
how you move in your environment as a survival advantage
63
what is taxis
directed movement in either positive or negative
64
what is conesis
undirected movement
65
what is positive taxis
movement towards a stimulus
66
what is negative taxis
movement away from a stimulus
67
how can you detect flagellin
with H-antigen
68
what is a eukaryotic flaella
extension of cell membrane around the flagella (made of microtubules) (9+2)
69
what is a prokaryotic flagella
filament made of flagellin aggregated together into a flagella, not an extension of the cell, cell membrane does not surround (more like a plug)
70
what is the function of MOT proteins
harness energy from the PMF and channels ions (gives energy to rings to move)
71
what is the function of FLI proteins
located between C and MS rings and act as a switch to initiate or deactivate PMF (for movement of the rings)
72
what direction is CW
reverse
73
what direction is CCW
forward
74
what is the C ring
cytoplasm
75
what is the MS ring
membrane space
76
what is the P ring
peptidoglycan
77
what is the L ring
LPS ring (only in G-)
78
where does the turning force for a flagella come from
the C and MS rings
79
how many flagella for monotrichus
1 polar or 1 lateral
80
how many flagella for amphitrichus
1 flagella at each end of the cell
81
how many flagella for lophotrichus
tuft of flagella either on one end or on both ends
82
how many flagella for peritrichus
ring of flagella surrounding entire cell
83
what is a basal body
prokaryotic molecular protein based motor
84
what are stators in prok motility
stators are the same at MOT proteins
85
what is it called when there is random run and tumble with no direction
conesis
86
what changes the direction of bacteria while they tumble or while they stop running
brownian motion will reorient them
87
what type of motility do type 4 pili have
twitching motility
88
what protein makes up fimbrae
fimbrin
89
what protein makes up pili
pilin
90
what are characteristics of fimbrae
short, sticky, thin, numerous
91
what are characteristics of pili
1 or 2, longer, thicker, help with complete conjugation (exchange plasmal DNA)
92
what is the function of cytoplasmic inclusions
used for energy storage
93
what is the function of PHA in cytoplasmic inclusion
energy storage
94
what does PHA stand for
polyhydroxylalkanoate
95
what is sulfur used for in cytoplasmic inclusion
its common, specialized and is anoxygenic
96
what is glygogen used for in cytoplasmic inclusion
access carbon and nitrogen, cant pass membrane due to size, solute conc for osmosis
97
what is polyphosphate used for in cytoplasmic inclusion
granules
98
what is a divisome
its the body responsible for division of prok cells
99
where is the divisome located
cell membrane and cytoplasm
100
what is FTSz in prok homologous to in euk
tubulin (cytoskeletal elements)
101
what does homologous mean
common evolutionary function
102
what does analogous mean
similar function
103
what are microtubules of euk
chains of tubulin
104
what does FTSz do in prok
forms a ring on inner cytoplasm at the center of the cell (part of divisome)
105
what is the function of zipA
anchors FtsZ (kind of like its glue), and recruits other divisome proteins to the site
106
what is FtsA homologous to in euk
actin
107
what is FtsI analogous to in euk
penicillin bringing protein
108
what does fts stand for
filamentous temperature sensitive
109
what is the function of FtsK
DNA binding protein that helps to partition DNA
110
what shrinks the FtsZ ring
depolymerization (ring shrinks and pulls membrane along with it but not the cell wall)
111
what pinches the cell wall so the cell can split
FtsI (makes new cell wall material)
112
how does a cell know where to partition
by the min proteins (min C and min D oscillate moving pole to pole and this defines the center of the cell)
113
what is the function of minE
removes the inhibition set by minCD and allows septum formation
114
what must daughter cells do before they can divide themselves
they must grow to the size of the mother cell before they can divide
115
what is the function of MreB
cycles the cell and hits in specific places, where it hits FtsI is able to generate new cell wall (lengthens the cell)
116
why are cocci spherical not elongated
they have no MreB
117
what causes spirillum
cresentin (acts the same way as MreB but it causes spiral not elongation)
118
what does it mean that prok have a high biotic potential
they can increase their population size rapidly
119
what is unrestricted growth and how is it made possible
bacteria can grow as fast as they want and its possible if the best possible conditions are made available to the bacteria. only under perfect conditions
120
rate of population growth is proportional to _____
initial population
121
what kind of growth is binary fission
exponential
122
what is n
number of generations
123
what is t
time over which growth occurs
124
what is g
generation time
125
what is k
specific growth rate constant
126
what is N
population size
127
how do you calculate n
log(N/N0)=n*log2
128
how do you calculate N
N=N0*2^n
129
how do you calcuate g
g=t/n
130
whats another term for generation
division cycle
131
how do you calcuate change in population over time
(delta N/N)=kdeltat
132
how do you determine k
must be determined under set conditions
133
what are the different stages/phases of bacterial growth
lag, exponantial (log), stationary, death
134
if you grow an oragnism on a different media what also must you do
generate a new growth curve
135
when getting a growth curve what do you record growth as
CFU/mL
136
what does CFU stand for
colony forming units
137
what is lag
period of physiological adaptation
138
what is exponential (log)
unrestricted growth (growing as fast as it can with the given conditions)
139
what is stationary growth
where the bacteria will cap out because the growth becomes restricted
140
what is death phase
cannibalism of cannibals, extension of waste products, death will dominate
141
why are theoretical equations so important for bacteria
bacteria are so simple that they follow theoretical equations well (theo mimics real life)
142
what is balanced growth
during unrestricted growth if all chemical constituants increase by the same proportion over the same time interval (all chemical increasing at same rate)
143
what is optical density
absorbance
144
what is an example of why balanced growth is helpful
measure DNA of one cell then measure all DNA present to determine the number of cells
145
what is a direct method of measuring population growth
counting the number of cells directly or CFU's directly
146
what is an indirect method for determining population growth
(assuming balanced growth)
| turbidity, measure cell dry weight, measure cell constituants (ex measure all DNA)
147
what are factors that affect microbial growth
chemical and physical
148
what are chemical microbial growth factors
chemicals needed to be fed (nutrition)
149
what are physical microbial growth factors
pH, salt concentration, heat
150
what is shelfords law of tolerance
in order to survive and reproduce in environment everything it needs must be in a specific range of existance
151
what does it mean that a cell needs macronutrients and micronutrients
macro and micro refer to amount needed not size of the molecule
152
what macronutrients are needed
CHNOPS (g/L)
153
how much of a cell does CHNOPS make up
about 95% dry weight
154
what are growth factors for a cell
usually things like vitamins and other small organic molecules
155
what are the 4 major organic molecule families
carbohydrates, proteins, nucleic acids, lipids
156
what elements make up carbohydrates
c, o, h
157
what elements make up proteins
c, h, o, n
158
what elements make up nucleic acids
c, h, o, p, n
159
what elements make up lipids
c, h, o
160
what type of organic molecules are usually used for carbon skeletons
sugar or proteins
161
where can an organism get carbon from
either from organic molecules or from carbon dioxide
162
when are organisms that use organic carbon
heterotrophs
163
what are organisms that use inorganic carbon
autotrophs
164
where do heterotrophs (organic) get nitrogen
proteins
165
where do inorganic (autotroph) get nitrogen
ammonia, ammonium, nitrate
166
how does a heterotroph get P
uses inorganic since organic forms are toxic (NaP, phosphate)
167
where do autotrophs get P
NaP, Phosphate
168
how do heterotrophs get S
amino acids
169
how do autotrophs get S
sulfate salts
170
how do organisms get minor macronutrients
try to use as salts with other major macros ex. potassium phosphate
171
what are the micronutrients
mostly transition metals (zinc, copper, iron, boron)
172
what is the main function of micronutrients
catalytic capabilities to make enzymes properly active (catalyst so substrates can bind)
173
what is a cofactor
organic
174
what is a coenzyme
inorganic
175
what are examples of growth factors
some amino acids (NAD, FAD)
176
why would something need growth factors
if micro and macro cant meet needs then can be met with growth factors
177
what is the purpose of growth media
to provide nutrients so organisms can grow
178
what are the two types of media
complex media and defined media
179
what is a complex media
contains complex ingredients (ex. enzyme digests of proteins or blood)
180
when would you use a complex media over a defined media
when you want generalized growth
181
what is defined media
contains specific ingredients in known amounts (chemically defined recipe)
182
when would you use a defined media over a complex media
usually used in research since there is no nutrient variance
183
what kinds of organisms need defined media
fastidious molecular organisms (picky ones who need very specific nutrients)
184
what does optimum temperature mean
the temperature at which the growth rate of an organism is at its highest (reproduce fastest)
185
what are biochemical reactions driven by in MO
enzymes
186
what is membrane gelling and when does it occur
(think of olive oil) when membrane gets too cold it becomes solid, but at optimal temperature it is fluid and things can properly pass through the membrane
187
in order from lowest temp to highest temp what are the types of philes
psychrophile, mesophile, thermophile, hyperthermophile
188
what is the difference between facultative and obligate
facultative can tolerate , obligate requires
189
what are the pH philes
acidophiles, neutrophiles, alkalinophiles
190
what is an enterotoxin
an exotoxin produced by proteins of the cell and is released by the cell while they cell is still living
191
regarding halophiles, what are most microorganisms
non-halophiles meaning they dont like a lot of solute (salt)
192
what is an osmophile
solute (based on osmotic effects)
193
what is a xerophile
can they tolerate dry conditions
194
all halophiles are osmophiles but what makes this distinction
halophiles have to do with sodium osmoregulation while osmophiles in general deal with solute osmoregulation
195
which philes are of most medical importance of humans
nonhalophiles, neutrophiles, mesophiles
196
what are compatible solutes
an increase in the concentration of compatible solutes in a cell does not make things toxic for the cell (adjusts cell water activity)
197
what are some examples of compatible solutes
betanes, mannitol, glycerol
198
what are the classification types for oxygen tolerance
obligate aerobes, microaerophiles, facultative anaerobes, aerotolerant anaerobes, obligate anaerobes
199
what is the purpose of using a roll tube
keep the agar within slightly warmer than solidification temp so you can test oxygen requirements
200
what is obligate aerobes
only grows where these oxygen (required)
201
what is microaerophiles
can tolerate some oxygen but prefers not
202
what is facultative anaerobe
prefers oxygen but can tolerate no oxygen
203
what is aerotolerant anaerobe
doesnt give a fuck about oxygen
204
what is obligate anaerobe
cannot tolerate oxygen
205
how is there a difference between needing oxygen and not being able to have oxygen
oxygen is toxic and those who have ways to deal with it require it, if an organism doesnt have ways to deal with it then it cannot survive in its presence
206
what essentially is metabolism
electron transfers between molecules
207
how many electrons are requires to reduce O2 to H2O
4 electrons
208
what happens when only one electron added to O2
superoxide anion
| a free radical and negatively charged O2 (anion)
209
what happens when 2 electrons added to O2
peroxide anion
| negatively charged O2 (anion)
210
what happens when 3 electrons added to O2
hydroxyl free radical
| no longer an anion but a free radical is present (most toxic)
211
how do organisms deal with toxic O2 derivatives
by producing enzymes
212
what are the main enzymes we deal with that help with toxic forms of oxygen
catalase (CAT) and superoxide dismutalase (SOD)
213
what enzymes do strict aerobes have
CAT and SOD
214
what enzymes do strict anaerobes have
none
215
what enzymes do facultative anaerobes have
CAT and SOD
216
what enzymes do aerotolerant anaerobes have
either CAT or SOD
217
what enzymes do microaerophiles have
a partially active SOD
