Cell Structure and Function in Bacteria and Archaea Flashcards
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1
Q
most common shape
A
cocci or rods
2
Q
determined by plane of division
determined by separation or not
A
arrangement
3
Q
spheres
A
cocci (singular: coccus)
4
Q
pairs of cocci
A
Diplococcus
5
Q
chains of cocci
A
Streptococcus
6
Q
grape-like clusters of cocci
A
Staphylococcus
7
Q
cylindrical shape
A
rod or bacillus
8
Q
very short rods
A
coccobacilli
9
Q
resemble rods, comma shaped
A
vibrios
10
Q
rigid helices
A
spirilla (spirillum)
11
Q
flexible helices
A
spirochetes
12
Q
network of long, multinucleate filaments
A
mycelium
13
Q
organisms that are variable in shape
A
pleomorphic
14
Q
What is the smallest size of bacteria?
A
0.3 µm (Mycoplasma)
15
Q
What is the average rod size of bacteria?
A
1.1-1.5x2-6µm (E. coli)
16
Q
What is the very large size of bacteria?
A
600x80 µm Epulopiscium fishelsoni
17
Q
important for nutrient uptake; surface to volume ratio
A
size-shape relationship
18
Q
True or False: small size may be protective mechanism from predation
A
true
19
Q
What are the bacterial cell organization common features?
A
cell envelope - 3 layers
cytoplasm
external structures
20
Q
selectively permeable barrier, mechanical boundary of cell, nutrient and waste transport, location of many metabolic processes (respiration, photosynthesis), detection of environmental cues for chemotaxis
A
plasma membrane
21
Q
inclusion that provides buoyancy for floating in aquatic environments
A
gas vacuole
22
Q
protein synthesis
A
ribosomes
23
Q
storage of carbon, phosphate, and other substances
A
inclusions
24
Q
localization of genetic material (DNA)
A
nucleoid
25
In typical Gram-negative bacteria, contains hydrolytic enzymes and binding for proteins for nutrient processing and uptake; in typical Gram-positive bacteria, may be smaller or absent
periplasmic space
26
protection from osmotic stress, helps maintain cell shape
cell wall
27
resistance to phagocytosis, adherence to surfaces
capsules and slime layers
28
attachment to surfaces, bacterial conjugation and transformation, twitching and gliding motility
fimbriae and pili
29
swimming and swimming motility
flagella
30
survival under harsh environmental conditions
endospore
31
What are the 3 layers of bacterial cell envelope?
plasma membrane
cell wall
layers outside the cell wall
32
thin barrier that surrounds the cell and separates the cytoplasm from the cell's environment
bacterial plasma membrane
33
'gatekeeper' for substances that enter and exit the cell
bacterial plasma membrane
34
True or False: bacterial plasma membrane absolute requirement for all living organisms
true
35
contains both polar ends and non polar tails
amphipathic lipids
36
interact with water
hydrophilic
37
insoluble in water
hydrophobic
38
loosely connected to membrane; easily removed
peripheral membrane protein
39
amphipathic-embedded within membrane; carry out important functions; may exist as microdomains
integral
40
gives structural integrity
hopanoid
41
comparison of hopanoid in mycoplasma
sterol
42
rigid structure that lies just outside the cell plasma membrane
peptidoglycan
43
What are the two types of peptidoglycan based on Gram stain?
Gram-positive and Gram-negative
44
stain purple; thick peptidoglycan
gram-positive
45
stain pink or red; thin peptidoglycan and outer membrane
gram-negative
46
What are the cell wall functions?
confers shape and rigidity on the cell
helps protect cell from osmotic lysis
helps protect from toxic materials
may contribute to pathogenicity
47
polysaccharide composed of two sugar derivatives (N-acetylglucosamine and N-acetylmuramic acid) and a few amino acids
peptidoglycan
48
What are the two sugar derivatives of peptidoglycan?
N-acetylglucosamine
N-acetylmuramic acid
49
Meshlike polymer of
identical subunits
forming long strands (alternating D- and L- amino acids)
peptidoglycan
50
What is the shape of peptidoglycan strands?
helical
shape
51
Peptidoglycan chains are crosslinked by ______ for strength
peptides
52
Composed primarily of
peptidoglycan; May also contain teichoic
acids (negatively charged)
gram-positive cell walls
53
# true or false
some gram-positive bacteria
have layer of proteins on
surface of peptidoglycan
true
54
# true or false
some gram-negative bacteria
have layer of proteins on
surface of peptidoglycan
false
| gram-positive
55
Usually composed of
polysaccharides
Well organized and not
easily removed from cell
Visible in light microscope
capsules
56
protective advantages of capsules
* resistant to phagocytosis
* protect from desiccation
* exclude viruses and detergents
57
similar to capsules except diffuse,
unorganized and easily removed
slime layers
58
slime may aid in
motility
59
Regularly structured
layers of protein or
glycoprotein that self-assemble
s layers
60
the S layer
adheres to outer
membrane
gram-negative bacteria
61
it is associated
with the peptidoglycan
surface
gram-positive bacteria
62
What are the S-layer functions?
Protect from ion and pH fluctuations, osmotic
stress, enzymes, and predation
Maintains shape and rigidity
Promotes adhesion to surfaces
Protects from host defenses
Potential use in nanotechnology
63
what are the bacterial cytoplasmic structures?
* Cytoskeleton
* Intracytoplasmic membranes
* Inclusions
* Ribosomes
* Nucleoid and plasmids
64
plasma membrane and
everything within
protoplast
65
material bounded by the plasmid
membrane
cytoplasm
66
What are the 3 eukaryotic cytoskeletal elements in bacteria?
Tubulin homologues
Actin homologues
Intermediate Filaments Homologues
(Unique Bacterial Cytoskeletal Proteins)
67
What are the different tubulin homologues?
FtsZ
BtubA/BtubB
TubZ
68
What are the different Actin Homologues?
MamK
MreB/Mbl
ParM
69
What are the different types of Intermediate Filament Homologues?
CreS (crescentin)
70
What are the different types of unique bacterial cytoskeletal proteins?
MinD
ParA
71
functions in cell division and is widely observed in bacteria and archaea
FtsZ
72
observed only in Prosthecobacter spp.; thought to be encoded by eukaryotic tubulin gens obtained by horizontal gene transfer
BtubA/BtubB
73
possibly functions in plasmid segregation; encoded by large plasmids observed in members of the genus Bacillus
TubZ
74
functions in positioning magnetosomes, observed in magnetotactic species
MamK
75
helps determine cell shape, may be involved in chromosome segregating, localizes proteins; most rod shaped bacteria
mreB;Mbl
76
functions in plasmid segregation; plasmid encoded
ParM
77
induces curvature in curved rods; found in caulobacter crescentus
CreS (crescentin)
78
prevents polymerization of FtsZ at cell poles; found in many rod-shaped bacteria
MinD
79
segregates chromosomes and plasmids; observed in many species including Vibrio cholerae, C. crescentus, and Thermus thermophilus
ParA
80
many bacteria; forms ring during septum formation in cell division
FtsZ
81
many rods; maintains shape by positioning peptidoglycan synthesis machinery
MreB
82
rare, maintains curve shape
CreS (crescentin)
83
– observed in many photosynthetic bacteria and many bacteria with high respiratory activity
plasma membrane infoldings
84
organelle – site of anaerobic ammonia oxidation
Anammoxosome in Planctomycetes
85
Granules of organic or inorganic material that
are stockpiled by the cell for future use;
inclusions
86
may be referred to as microcompartments
inclusions
87
Storage of nutrients, metabolic end products,
energy, building blocks; glycogen storage, carbon storage
storage inclusions
88
Polyphosphate (Volutin)
phosphate
89
cyanophycin granules
amino acids
90
Not bound by
membranes but
compartmentalized for
a specific function
microcompartments
91
CO2
fixing bacteria
carboxysomes
92
contain the enzyme
ribulose-1,5,-
bisphosphate
carboxylase (Rubisco),
enzyme used for CO2
fixation
Carboxysomes
93
found in aquatic, photosynthetic bacteria and
archaea; provide buoyancy in gas vesicles
gas vacuoles
94
found in aquatic bacteria; magnetite particles for orientation in Earth’s magnetic field; cytoskeletal protein MamK
magnetosomes
95
sites of protein synthesis
ribosomes
96
bacterial and archaea ribosome
70s
97
eukaryotic ribosome
80s
98
bacterial ribosomal RNA
16S small subunit
23S and 5S in large subunit
99
Location of chromosome
and associated proteins; Usually 1 closed circular,
double-stranded DNA
molecule
nucleoid
100
found in bacteria, archaea, some fungi; usually small, closed circular DNA molecules
Extrachromosomal DNA
101
plasmids that may integrate into chromosome
episomes
102
Extend beyond the cell envelope in bacteria
external structures
103
Function in protection, attachment to
surfaces, horizontal gene transfer, cell
movement
external structures such as:
pili and fimbriae
flagella
104
short, thin, hairlike,
proteinaceous appendages (up to
1,000/cell)
fimbriae; pili
105
can mediate attachment to
surfaces, motility, DNA uptake
Fimbriae (s., fimbria); pili (s.,
pilus)
106
longer, thicker, and less
numerous (1-10/cell); genes for formation found on
plasmids; required for conjugation
sex pili
107
Threadlike, locomotor appendages extending
outward from plasma membrane and cell wall
flagella
108
functions of flagella
motility and swarming behavior
attachment to surfaces
may be virulence factors
109
Thin, rigid protein structures that cannot be
observed with bright-field microscope unless
specially stained; Ultrastructure composed of three parts
bacterial flagella
110
what are the different patterns of flagella distribution?
Monotrichous
Polar flagellum
Amphitrichous
Lophotrichous
Peritrichous
111
one flagellum
monotrichous
112
flagellum at end of cell
polar flagellum
113
one flagellum at each end of cell
Amphitrichous
114
cluster of flagella at one or both ends
lophotrichous
115
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flagella spread over entire surface of cell
peritrichous
116
What are the three parts of flagella?
filament
hook
basal body
117
extends from cell surface to the tip; hollow, rigid cylinder of flagellin protein
filament
118
links filament to basal body
hook
119
series of rings that drive flagellar motor
basal body
120
complex process involving many genes/gene
products where new flagellin molecules transported through the hollow filament using Type III-like secretion system; filament subunits self-assemble with help of filament cap at tip, not base
flagellar synthesis
121
What are the different motility?
flagellar movement
spirochete motility
twitching motility
gliding motility
122
move toward chemical attractants such as
nutrients, away from harmful substances
chemotaxis
123
Move in response to temperature, light,
oxygen, osmotic pressure, and gravity
motility
124
Flagellum rotates like a
propeller
125
how many revolutions per sec is bacterial flagellar movement?
1100 rev/sec
126
causes forward motion (run)
counterclockwise
127
disrupts run causing cell to stop and tumble
clockwise rotation
128
2 part motor
producing torque
flagellum
129
2 parts producing torque of flagellum
rotor and stator
130
C (FliG protein) ring and MS ring
turn and interact with stator
rotor
131
Mot A and Mot B proteins that form channel through plasma
membrane
stator
132
protons move through Mot A and
Mot B channels using
energy of proton motive force
133
powers rotation of the
basal body and filament
torque
134
Multiple flagella form axial fibril which winds around
the cell; Flagella remain in periplasmic space inside outer
sheath
spirochete motility
135
exhibits flexing and spinning
movements
corkscrew shape
136
May involve Type IV pili and slime
twitching and gliding motility
137
pili at ends of cell; short, intermittent, jerky motions; cells are in contact with each other and
surface
twitching
138
smooth movements
gliding
139
Movement toward a chemical attractant or
away from a chemical repellent
chemotaxis
140
Changing concentrations of chemical
attractants and chemical repellents bind
chemoreceptors of chemosensing system
chemotaxis
141
# True or False
In presence of attractant tumbling frequency is
intermittently reduced and runs in direction of
attractant are longer
true
142
# true or false
In presence of attractant tumbling frequency is
intermittently increased and runs in direction of
attractant are longer
false
| tumbling freq is reduced
143
# true or false
In presence of attractant tumbling frequency is
intermittently reduced and runs in direction of
attractant are shorter
false
144
Complex, dormant structure formed by some
bacteria
bacterial endospore
145
bacterial endospore is resistant to numerous environmental conditions such as:
heat
radiation
chemicals
dessication
146
what makes an endospore so resistant?
calcium
small, acid soluble, DNA-binding proteins (SASPs)
Dehydrated core
Spore coat and exosporium protect
147
* Process of endospore formation
sporulation
148
how many hours does sporulation occurs?
up to 10 hours
149
Normally commences when growth ceases
because of lack of nutrients; Complex multistage process
sporulation
150
What are the different parts of Formation of Vegetative cell?
Activation
Germination
Outgrowth
151
prepares spores for germination; often results from treatments like
heating
activation
152
environmental nutrients are
detected; spore swelling and rupture of
absorption of spore coat; increased metabolic activity
germination
153
emergence of
vegetative cell
outgrowth
154
more permeable than plasma membrane due to presence of porin proteins and transporter proteins
gram negative
155
form channels to let small molecules
(600–700 daltons) pass
porin proteins
156
solute concentration outside the cell is less
than inside the cell
hypotonic environments
157
water moves into cell and cell swells; cell wall protects from lysis
hypotonic environments
158
solute concentration outside the cell is greater
than inside
hypertonic environments
159
– water leaves the cell
– plasmolysis occurs
hypertonic environments
160
how can cells lyse in hypotonic solution?
lysozyme breaks the bond bet N-acetylglucosamine and N-acetylmuramic acid
pennicillin inhibits peptidoglycan synthesis
161
cells that lose a cell wall that may survive in isotonic environments
protoplasts
spheroplasts
mycoplasma
162
does not produce a cell wall; plasma membrane more resistant to osmotic
pressure
mycoplasma
