Midterm 2 material Flashcards
1
Q
Define: F0F1 ATPase
goal?
characteristics? 3 total
where is it found?
A
goal: to pump protons to other side of mem
Reversible process
Ubiquitous + highly conserved
F1 and F0 oriented in opposite directions
Found in mito mem of eukaryotes OR mem of prokaryotes
2
Q
location of F1 + F0 in the cell and their role
A
F1 - free in the outside of cell
It’s the catalytic site for ATP synthesis
F0 - bound to interior of mem
acts as a rotary motor powered by the flow of protons
3
Q
what are the subunits of F0?
A
F0: 3 subunits - all are integral mem components
1. A - embedded in mem
2. B - connects F0 + F1
A + B = Provide a channel for proton flow + interacts with the rotor to generate torque
3. C also known as C ring - has 12 subunits
4
Q
what are the subunits of F1?
also something is impaled
A
F1: Gamma + Epsilon - 2 total philic subunits acting as a rotating rod
Alpha - has NO catalytic function; Only holds structure together
Beta - hydrophilic w/ small hydrophobic region; Phobic region = anchor
Alpha + beta subunits impaled by gamma
5
Q
What is the rotor + stator of F0F1 ATPase? what subunits form each part?
A
Rotor + stator - a combination of subunits from both F0 and F1
Rotor: c subunit (from F0) + gamma subunit (from F1)
- Rotating component
Stator: a + b subunit (from F0) + alpha + beta subunit (from F1)
- Stationary component
6
Q
What is the driving force of F0? F1?
A
F0 = PMF
F1 = ATP hydrolysis
proton gradient generates ATP
7
Q
what happens to the F1 ATPase normally + when it changes direction? what happens per
revolution?
A
Normally, F0 forward + F1 in reverse; ATP synthesis driven by PMF
F1 moving forward, towards ATP hydrolysis; 3 ATP hydrolyze/revolution
F1 moving in reverse; 3 ATP synthesized/revolution
8
Q
what is the bacterial flagella?
A
hair like structures that propel bacteria through liquid environments
9
Q
what is the bacterial flagella made of?
A
- basal region w/ 4 rings…
- A pipe
- Hook
- HAP1 + 3
- HAP2
10
Q
rings associated w/ the basal region of the bacterial flagella? 4 total rings
A
(A) C ring associated w/ motor
(B) M ring associated w/ mem
(C) P ring (peptidoglycan binding motif) associated w/ stator - Allows for motor to be stabilized via anchoring
(D) L ring associated w/ LPS - Lipopolysaccharide
11
Q
what is the purpose of the bacterial flagella’s pipe? 3 points
A
Allows transport of export substrate
Leads to lengthening of tail
Goes through all the rings
12
Q
what is the purpose of HAP1 + 3 and HAP2?
A
HAP1 + 3 - Responsible for linking hook + basal region
HAP 2 - Cap that causes flagellum to stop growing
13
Q
What is the order of synthesis of the bacterial flagellum? what is the driving force?
A
(first) basal region → hook → flagellum (last)
Driving force… proton motive force
14
Q
What is the direction of the flagellum?
A
flagella move in direction of something good + away from bad things
15
Q
What is the purpose of MotAB? what do they make up?
A
Components A+B s crucial for the function of the bacterial flagellar motor
make up the stator, acting as channel for proton
16
Q
What forms a complex that interacts w/ MotAB? what happens if no comples interaction? 3 points
A
FliG, M, N form a complex that interacts w/ MotAB
No complex interaction, then…
1. No intact flagella
2. Intact flagella w/ no motor
3. Intact flagella w/ no chemotaxis
17
Q
how is the flagella constructed + what can control its length?
A
T3SS (Type 3 secretory system) - crucial for assembly of components outside of mem
- Components that traveled through hollow flagellum tube added to end of tail
Capped by HAP2 - stop growth
- Completion of Hook + basal body = crucial checkpoint
FliK regulates hook length - an internal “ruler”
18
Q
what happens when the switch between swarming + swimming occurs? how do the swarming cells looks?
A
Switch between swarming + swimming = change in morphology
Swarming cells more elongated + flagellated
19
Q
differences between archaea + bacterial flagellum
6 points
A
-diff structure + function
-Driven by ATP hydrolysis NOT PMF or SMF
-Slower + thinner than bacteria
-Archaea has no peptidoglycan in cell wall
-New subunits assemble @ base andare diff (Bacteria subunits assemble @ tip)
-Flagellum - no hollow space
20
Q
similarities between archaea + bacterial flagellum
A
-have Flimanet + basal region + hook too
- Use the same homologous chemotaxis proteins
21
Q
compare the motors between archaea + flagellum
what aa are used?
A
Motors are diff
Bacteria: use proton/sodium channels + serine or threonine
Archaea: they use ATP to drive the process
- Its an aspartate + asparagine aa derivative
22
Q
sodium motive force (SMF)
what does it do?
A
-provide energy
-bacteria useS PMF to power the rotation of the flagellum for motility
- archaea uses SMF to indirectly help ATP synthesis
23
Q
what does motility Type IV pili (T4P) controls + how?
A
- movement over surfaces w/o flagella
- Uses cell propulsion
24
Q
steps in cell propulsion. 3 total
A
- pilus extension
- Attachment to a surface
- Retraction
25
why is the assembly of pili rapid?
due to genome economics - Rapid assembly from newly synthesized monomers due to high rate of new protein synthesis
recycles primary pilA
26
what is Gliding movement? what is it powered by? what protein does it use? what is the motor comprised of?
a type of lateral movement on solid surfaces, Powered by PMF
Uses SprB adhesin - an adhesive organelle used to grab onto something
Motor used in gliding movement comprised of GLD proteins
27
function of SprB aka what does it attach to? what allows for movement? when does movement occur? it rotates over what?
-attaches itself to the surface
-undergoes conformational changes that allow for movement
- Movement occurs during retraction conformational stage
-SprB rotates over lateral surface
28
what is lateral movement? what is an example aside from gliding? what is it powered by?
made up of several diff sideways movements
Ex. twitching
Powered by ATP hydrolysis
29
define the two forms of motility: S + A motility
S motility - a type of twitching motility
A motility - polysaccharide secretion generates propulsion; Slime trail left behind
30
what 2 things can be secreted to produce cell propulsion
31
what uses the centipede + inchworm motility methods?
what is it?
Mycoplasma - tiny bacteria w/ simple genome + asymmetric built - move w/ head direction
32
explain centipede + inchworm motility
Gli proteins localized @ neck allow for Leg like function leading to centipede like movement
Are able to glide in the direction of terminal organelle where terminal cytoskeleton forms dynamic motor; Leads to inch worm like confirmation changes
33
why does the outside of a cell have a pH of 5.5?
outside of cell more acidic bc of high [H+] protons; [high] given protons are pumped out of cell producing proton gradient
34
why is the F0F1 ATPase reversible?
because of two possible energy sources, ATP hydrolysis + PMF
35
which way is the F0F1 ATPase rotating to promote the PMF? ATP synthesis?
ATP hydrolysis + CW rotation = PMF
PMF + CCW rotation = ATP synthesis
36
which AA residue is essential for transferring H+ ions (protons)
Aspartate/Aspartic acid (D)
D61
37
which AA residues are essential for the channel to function
D61 + Arginine (R)/R210
38
where does the ATP binds + the general steps in the F1 component
ATP binds beta subunit
General steps
1. ADP + Pi binds
2. ATP synthesis
3. ATP leaves
39
why is the flagellar motility energetically significant?
Bc it takes half of all energy to rotate flagella + to allow movement
40
what functions together to produce the torque in the flagellar motor?
C-terminal domain of FliG interacts w/ MotAB to produce the torque
41
negative cooperativity
binding of 1 or more ligand molecules to a multimeric receptor makes it difficult for other ligand molecules to bind
42
what is negative cooperatively due to?
receptor clumping +
(receptor) methylation
43
why is chemotaxis so important?
important amongst bacterial flagella for successful host colonization + infection
Generally, important for survival + growth + directed movement away from bad environment, towards good environment
44
how is tumbling caused? how can tumbling direction change? CW or CCW rotation?
Tumbling is a result of temporary reversal in the rotary direction of flagellar motors
increasing repellent causes tumbling to go another direction
Bacteria disperse in CCW rotating leading to tumbling
45
which step of the signal transduction rxn is faster? which is sower? is faster attributed to tumbling or swimming? how about slower?
1. Activation step = fast
Fast rxn for tumbling, heading in a different direction
2. Adaptation step = slow
Slow rxn for swimming, heading in the correct direction
46
what is the role or CheA? CheW? what do they accomplish together?
CheA - histidine kinase
CheW - adaptor protein
CheA+CheW = form complex that primarily clusters @ poles to control clumping
47
CheR + CheB's purpose? what are the domains of CheR? CheB? Hint: both have 2 domains
de/methylate specific residues
CheR has 2 domains
1. N for MCP binding only
2. C for MCP binding + catalysis
CheB has 2 domains
1. Phosphorylatable receiver/regulatory domain
2. Catalytic methylesterase domain
48
connection between chemotaxis and environmental niches?
Bacteria use chemotaxis to accumulate in environmental niches that provide optimal conditions for growth
49
significance of nutrient or repellent gradients? aka what movement happens if there is an increase in attractant/nutrient? an increase in repellent
Both act as signals
An increase in attractant (nutrient) leads to smooth swimming; For moving towards nutrient rich environments
An increase in repellent (toxic substance) leads to tumbling; For moving away from toxic environments
50
trade-off between nutrients and motility
Accumulation of nutrients leads to increased nutrient uptake
-Advantage: Leads to enhanced growth + swimming motility
-Disadvantage: requires high investment of cellular resources
-Solution: swim for food when it's abundant but conserve energy when food is scarce
51
significance of cAMP? what happens under high cAMP?
cAMP is important for determining regulation of flagellar genes
Reflects growth rate under carbon limited conditions
High cAMP under limited conditions activates alternative uptake + metabolism routes for diff energy sources
52
connection between trade-offs and variability as well as niche formation? when does variability decrease?
chemotactic performance variability in bacterial pops exists
Run + tumble of bacterial swimming + chemotactic sensitivity = varies within cells
Variability decreases @ high levels of chemoattractants
53
when is tradeoff in flagellar motility + chemotaxis of bacterial pathogens most beneficial? what will happen later in the process ?
beneficial @ early stages of infection
Later becomes too much given flagellum = major antigen thats recognized by immune system
54
why is the flagellum detrimental to pathogens?
Flagellum = major antigen recognized by immune system
55
Chemotactic responses occur due to...
| what type of patterns
emergence of higher complexity patterns
56
what is the chemotactic response? what does it lead to?
Bacteria responding to chemicals released by other bacteria
Leads to chemotactic self-attraction, generating aggregative processes
57
what happens at higher densities of cells and swimming?
cell swimming leads to physical interactions between bacteria
58
how is the flagellum beneficial at surfaces?
Flagellum promotes initial attachment to a surface
59
why is the flagellum beneficial for pathogenic bacteria? 3 reasons?
Higher interaction w/ mucus layer
Increased chance of penetration into host cell
Helps w/ colonization
60
what is the Rhizosphere? what taxis does it use? what is the purpose?
-an area in the soil surrounding plant roots
-Rhizosphere pathogenic bacteria uses chemotaxis
-Purpose is to accumulate towards nutrient rich environment around plant route
61
Adhesion to the surface helps w/…
adhesion to surface is what stage in the development of biofilms?
resistance to antibiotics via enhancing stability of plasma mem
It is the initial stage in development of biofilms
62
Biofilms are important for...
survival + proliferation + protection against agents
63
concept of flagella impedance?
Where surface sensing is mediated via proximal surface interfeing w/ rotation of bacterial flagella
64
characteristics of Type IV pili (T4P): what are they? how are they extended? what kind of motility used?
They are mem bound filamentous structures
Extended via polymerization by an assembly ATPase
Perform twitch motility
65
Pseudomonas aeruginosa
what are they?
what kind of injury is it common w/?
what sickness can it cause?
what kind of flagella does it contain?
can it attach to the surface? detach? for how long?
-Pathogen w/ acute or chronic effects
-Common w/ infections of burns
-Can cause cystic fibrosis
-Contains polar flagella
-Attaches + detaches to surface temporarily
66
what if P aeruginosa remain attached to the surface? what kind of surface is required?
if attached, then its irreversible, halting flagella rotation
Require physically rigid surface, not specific chemical surface composition
67
what is quorum sensing?
Sensing of cell pop density, regulating gene expression
68
E. coli and its characteristics
is it commensal or harmful bacteria?
how does it regulate virulence?
what 3 things does it use to mediate diseases as virulence factors?
what happens in response to changes in physical force?
Can be commensal bacteria + common health concerns as a virulent strain
Regulates via mechanosensors
Uses type 3 sec system + adhesins + toxins
Expression of virulence factors are altered
69
what is the motility speed of E coli in soft agar?
Pathogenic strains had increased motility, Commensal bacteria had normal motility speed
70
What does mechanosensing of E coli help with? how? what is motility useful for?
helps w/ successful host colonization via increasing expression of flagella in early infection stages
Motility useful in promoting contact w/ epithelial cells during early stages of infection
71
what happens when V. Cholerae cannot use the flagella
Defective motility leads to enhanced expression of virulence factors like toxins
72
what are the functions + characteristics of pili based nanowires? 3 total
Conductive in absence of native metal cofactors + added metals
Function as conduits for long range e- transport → extracellular terminal e- acceptors
More conductive due to higher aromatic aa abundance
73
how can certain amino acid residues increase conduction
Close packing of aromatic aa during filament assembly forms aromatic-to-aromatic e- conduction paths thereby increasing conduction
74
what are some of the devices that use bacterial nanowires? 3 total
Sensors, electricity production, and memristors
75
MCPs and CheA - is activity stimulated or inhibited? when bound to repellent/attractant
Repellent-bound MCPs stimulate autokinase activity of CheA
Attract-bound MCPs inhibit autokinase activity of CheA
76
what happens when you add a repellent or an attractant
Add attractant, Leads to dimerization of TM1/TM2 monomers
Add repellent, monomers dissociate
77
what controls clumping?
CheA + CheW
78
methylation and clumping in negative cooperatively. What does negative cooperatively mean? what is it due to?
Negative cooperativity refers to the ability of sensing a [range]
Negative cooperativity due to clumping of receptors @ poles + receptor methylation
79
what components can control methylation
CheR + CheB
80
components of attractant binding + MCP methylation?
hint: what does binding create and becomes what to what? What is the purpose of SAM?
Binding creates conformational changes such that MCP = poor substrate of CheB but good substrate for CheR
SAM increases methylation, reducing attractant affinity by removing (-) charge thereby returning protein to inactive/condensed form
81
what induces lateral flagella use? six points
1. Increase viscosity = decrease rotation of polar flagella
2. Decrease rotation for growth on surfaces
3. Decrease rotation when antibody binds to polar flagellum
4. Decrease rotation when Na+ channels are blocked
5. Prevent rotation when there are muts in the flagellum constituents, blocking assembly
6. Prevent rotation when muts are in motor
82
what induces swarmin?
1. Halting cell division
2. Cell elongation
3. Induction of all swarmer cell genes
4. Induction of surfactin genes
83
what is TolQRA responsible for? how is it involved in drug resistance?
-responsible for transport of LPS to outer surface
-Indirectly involved in drug resistance as Tol mutants have leaky outer mems, altering drug sensitivities
84
Tsr, Tar, Trg and Tap which kinds of thermosensors are they?
Tsr + Trg = warm sensors
Tar - warm + cold sensors
Tap - cold sensor
85
what kind of motility is induced when warm or cold sensors experience changing temperatures?
Warm sensors experience temp decrease, they tumble
Cold sensors experience temp decrease, then smooth swimming
86
obligate and facultative bacteria [Oxygen]? what happens in high levels of O2 in Facultative?
Obligate aerobes - migrate to the air-water interface
Facultative aerobic bacteria - Seek optimal [oxygen] where high O2 levels can inhibit respiration
87
what are Magnetosomes? what are they made of? size comparison across all organisms? what about chain + magnetic moment orientation?
small cubo-octahedral crystals made of magnetite + greigite
Crystal size the same across all organisms
Chains have same orientation - Magnetic moments thus are all in the same direction
88
What does TatA do? How can TatA accommodate large/small subunits? when does it adjust to large subunits? what's the purpose of TatC?
TatA - creates size adjustable pore by changing amount of TMSs; Adjusts to large substrates only as needed
TatC - energizer
89
what are holins? what are they responsible for?
Form holes in mem - Are responsible for export of enzymes that cause cell wall degradation and eventually, cause lysis
90
why it is bizarre that the LolA/LolB pieces have a similar 3D structure?
Bc one is in a hydrophobic environment and the other in a hydrophilic environment
91
Explain how ABC systems (3 total) arose either in duplication of fusion + what they transport
Also explain how the 5 TMS of ABC 4 arose
ABC 1 - Duplicated or fused to other domains; Transport all substrates
ABC 2 - Rarely duplicated/fused; Export carbohydrates
ABC 3 - Often duplicated/fused to other domains w/ non-random arrangement; Transport peptides + proteins
5 TMS ABC 4 arose from either a 2 duplication plus 1 or 3 dup minus 1
92
inner mem sec system: Type 1
Allows transport across both mems of gram-neg envelope in single step
TolC - Forms trimeric outer mem beta barrel pore structure + trans-periplasmic trimeric alpha helical conduit, connecting inner mem permease to outer mem pore
OMF itself provides trans periplasmic channel
MFP interlinks inner + outer mem transport pathways
93
inner mem sec system: tat
| TatABC?
Translocate redox enzymes
Are channels for protein translocation
TatABC - 1 B homologue + C required for function
C is the specificity determinant for complex
94
inner mem sec system: Type 4
Made up of subunits that span 2 mems + peptidoglycan wall in gram-neg cell envelope + single mem pilus of gram-pos cell envelope
Export proteins + DNA protein complexes into cytoplasm of recipient cell + Also transfer DNA
95
inner mem sec system: Type 3
What do they secrete?
Do they secrete proteins directly into host cell cytoplasm w/o exposure to extracellular environment + Secret virulent factors?
Allow secretion of cytoplasmically synthesized proteins across both mems of cell envelope
YES
96
General secretory translocases (sec system) (type 2)
what are the e coli translocase constituents made up of? what are they know as?
What is the 2nd thing they are made up of? what are they known as?
Made up of heterotrimeric integral mem protein complex Known as SecYEG
Also made up of cytoplasmic ATPase known as SecA
Sec-dependent proteins export
97
in the sec system, are Integral mem protein insertions driven by ATP/GTP hydrolysis?
YES
98
What is the purpose of the PMF in the gen sec system?
PMF is stimulatory + functions in translocating C-terminal parts of unfolded proteins
99
Outer mem sec systems: FUP
Function: biogenesis of fimbriae/pili in gram-neg bacteria
Fimbrium specific periplasmic chaperone protein + outer mem usher protein
Pilus subunits bound to chaperone proteins; Prevents self assembly of pili in periplasm
100
Outer mem sec systems: TPS
They are large proteins w/ adhesive activities linked to bacterial virulence
Passenger domain exported across outer mem via transport constituents
101
Outer mem sec systems: AT-1
Made up of single protein w/ N-terminal sec type signal peptide + central passenger domain + C-term beta domain
Passenger domains determined by function of exo proteins
102
Outer mem sec systems: AT-2
Has YadA
Linker needed for stability + translocation of passenger domain through outer mem
103
Outer mem sec systems: OmpIP
what is it and what are the outer membrane proteins assembled from?
what are they involved in?
what happens if you decrease OMP83?
They are gram-neg bacterial outer mem proteins assembled from periplasm into outer mem
Involved in lipid biosynthesis
Decrease of Omp85 leads to accumulation of LPS in inner mem + loss in outer mem
104
are proteasomes found in eukaryotes? Archaea? bacteria? w/ what function?
Eukaryotes + archaea use proteasomes for protein degradation
Only certain bacteria have proteasomes with diverse functions
105
how is the function + structure similar and different to chaperones
Chaperone proteins fold unfolded proteins into native state while proteasomes degrade misfolded proteins
106
do proteasomes require ATP to function?
YES BUT NOT ALL
107
where do GQYL motifs insert themselves? why?
between alpha subunits to open M tuberculosis 20S CP gate
108
Proteolytic specificity is determined by...
the chemical nature of the pocket surrounding the active site.
109
nitric oxide (NO) resistance. what does it depend on? what does it damage? what are the effects of the damage?
NO resistance dependent on proteasomal degradation
NO can damage lipids + proteins + nuc acids, inhibiting microbial growth
110
copper (Cu) resistance. what is the expression of Copper inducible genes controlled by? what does it link? what is Cu considered? when is Rice activated?
- expression of copper-inducible genes controlled by a single transcriptional repressor, RicR, links proteasome-dependent degradation to copper (Cu) homeostasis
- Cu can be a nutrient but also a potent source of toxicity
-RicR is activated under conditions of elevated Cu
111
bacteria are not...
just a “bag of enzymes”
112
2 enzymes required for pupylation? what are they considered?
Dop (deamidase of Pup) + PafA (proteasome accessory factor A)
both are depupylases
113
is pupylation always involved in degradation?
NO
114
connection between propeptideless PrcB and 20S CP assembly?
Production of a propeptideless PrcB subunit significantly lowers the rate of 20S CP assembly
115
what are Mpa and ARC considered? what unfolding is a requisite for survival during iron starvation?
Both are AAA ATPases
ARC unfolding
116
when does quicker degradation occur?
Quicker degradation when bacteria grow under nitrogen starvation
117
Proteotoxic stress uses HspR, a regulon,...
required for heat shock resistance
118
what are the 2 halves of the internal cavity in bacteriorhodopsin? what parts do they compromise?
its divided into half channels
-cytoplasmic + external half channels
-comprise the two parts of the transmembrane H+ pathway
119
what 2 things produce torque? force exerted to what?
Large clusters of MotAB homologs interacting w/ MreB
exerted force to the surface
120
is retraction required for movement to occur?
YES
121
Do twitch + gliding motility require a surface or another cell to attach to?
YES
122
what stops random peptides from entering the proteasome and being degraded?
Alpha subunits of 20S CP harbor N terminal extension, preventing peptides from entering central protease chamber
123
3 essential functions of the proteasomal ATPases
1. Specific recognition of substrates
2. ATPase-driven unfolding
3. Engagement with 20S CPs to induce gate opening
124
What is AAA? what does it power? what is its defining feature of AAA ATPase unfoldases?
A domain that powers substrate delivery into the 20S CP
defining feature: a conserved aromatic-hydrophobic-glycine motif known as the pore loop
125
where does the pore loop extend into? what does it make direct contact w/?
into the channel of the ATPase
Makes direct contact with substrates.
126
what is Dop + what happens if its non functional + what does that demonstrate?
a depupylase
there will still be Pupylation but vast majority of Pup + substrates were degraded
illustrates requirement of DOP for removal + recycling of pup before proteasomal degradation
127
what is MPA + what happens if its non functional + will depupylation occur in the presence of MPA
Participates in depupylation
w/o Mpa, overproduction of Pup results in fast accumulation of pupylated ino1
depupylation occurs in the presence of Mpa
128
what discover did ATP independent proteasome activity lead to? what activator and amino acid motif is needed?
discovery of a non-ATPase proteasome activator PafE
or Bpa
activator: Bpa
motif: a c-terminal motif needed for 20S CP gate opening, specific to PafE which is only a gate opener, not unfoldase
129
bacterial cytoskeleton components + what are they key elements for?
5 components + 4 key elements
tubulins (FtsZ) + actins (MreB and ParM) + intermediate filaments (IF and crescentin) are key
elements for
1. cell division
2. chromosome + plasmid separation
3. cell shape and polarity maintenance,
4. organelle-like structure distribution
130
what are the pieces that organize DNA components + their role? 3 total
TubZ - a tubulin for plasmid segregation
PhuZ - replicates bacteriophage DNA in the cell's center
Crescentin - helps keep the helical shape of some strains
131
what is the role of SopA P-loop ATPase? does the polymerization of SopA occur @ the same rate for either chromosomal and plasmid segregation?
to segregate plasmids in E. coli
yes
132
which piece is the flagellar switch?
FliM(NFG) complex comprises the switch (gear box) + part of the motor
133
Sec systems are...
They are the...form
Universal; basic
134
function of carboxysomes? hint: what do they concentrate (2 things)? how (2 things)?
concentrate bicarbonate and CO2
use transport systems in the cell membrane + the
microcompartment
135
function of RuBisCO? is it considered the most prevalent enzyme on Earth? is its activity fast or slow? how much of this enzyme is needed?
CO2 fixation
YES, most prevalent enzyme on Earth
acts slowly
cells need a lot of it
136
what does Ethanolamine Utilization sequester? 2 things
volatile + toxic metabolites
137
what is in the sulfur granules (2 things)? can the sulfur in the granules be used as electron donor or acceptor in subsequent redox processes? Are they protective organelles?
redox-dependent energy generation and sulfur storage is the sulfur granule
YES
YES
138
What is the function of SecYEG? why is men transport harder for gram-negative bacteria?
SecYEG channel complex - where substrate proteins must pass to enter external surface of men or to be inserted into the mem
because it has 2 membranes
139
What is the ratchet system used for? Are polysaccharides rapidly propelled?
For cells to move rapidly over surfaces, Gld proteins are thought to comprise the multicomponent motor that propels the surface adhesin SprB.
YES
140
Adventurous motility vs social motility
Adventurous gliding motility (A-motility) involves movement of a single cell
Social motility - motility of a
mass of cells
141
what is the purpose for gas vacuoles to house air in the cytoplasmic membrane?
for floatation
142
characteristics of GroES and GroEL? what is unique about the surface of GroEL? what interaction of GroEL drives the folding of proteins? which one is the Cap or barrel?
GroES + GroEL = hydrophobic
surface of GroEL is hydrophilic
half hydrophilic + half hydrophobic interaction
GroES - the lid
143
do most of the “Somes” have lipid membranes, or at least traditional lipid membranes?
NO
144
Is Glucose the most thermodynamically stable sugar? Does this make it is the most prevalent sugar on the planet?
YES; YES
145
Is Cellulose an insoluble fibrous polymer of glucose? it is important for the formation of what?
YES
for biofilm formation
146
What can anammoxisomes do? what are the runs used for? why kind of unique lipids are they composed of?
where anammox reactions occur and are used for microbial nitrogen cycles
ladderane lipids
147
why did it take so long to discover anammoxisomes?
grow extremely slowly given unique lipid
148
why do Carboxysomes concentrate CO2?
to help with the inefficiency
149
exosomes/degradosomes: what do they degrade? what do they process?
RNA
process/modify small stable RNAs
150
cellulosomes: what is their function? how many domains in cohesive + what are they known as? what is the purpose of DD? what does cellulose bind?
function: Contain cellulose binding domains for binding crystalline cellulose, and a duplicated dockerin domain
-9 massive cohesive domains, known as cohesins
-large Dockerin Domain (DD) - anchors the protein to the cell wall
-Cellulose binds to a hydrophobic/hydrophobic interface in the scaffoldin’s cellulose binding domain (CBD)
151
about the 20S Core Particle (CP)
Is it a protease component of all proteasomes?
Is the mechanism of proteolysis by 20S CPs universal among proteasomes?
What lowers the rate of 20S CP assembly ?
YES
YES
production of a propeptideless PrcB subunit significantly
152
is 20S Core particle gated to prevent nonspecific entry of proteins?
In all domains of life, is the 20S CP a 28 subunit complex consisting of 4 stacked rings?
Are pupylation components always encoded by 20S CP subunit genes?
YES
YES
NO
