Cell Shape, Size, and Arrangement Flashcards
1
Q
sphere shape bacteria
A
Cocci (s., coccus)
2
Q
sphere-shaped bacteria in pairs
A
Diplococcus
3
Q
sphere-shaped bacteria in chains
A
Streptococcus
4
Q
grape-like clusters
A
Staphylococcus
5
Q
3-D cube bacteria
A
Sarcina
6
Q
cylindrical-shaped bacteria
A
Rod or bacillus
7
Q
very short rods
A
coccobacilli
8
Q
resemble rods, comma shaped
A
Vibrios
9
Q
rigid helices
A
spirilla (spirillum)
10
Q
flexible helices
A
spirochetes
11
Q
organisms that are variable in shape
A
pleomorphic
12
Q
smallest microorganism
A
0.3 micrometer (Mycoplasma)
13
Q
average rod
A
1.1 -1.5 x 2-6 micrometer (E. coli)
14
Q
very large microorganism
A
600 x 80 micrometer (Epulopiscium fishelsoni)
15
Q
Size-shape Relationship
A
- Important for Nutrient Uptake
- Surface to Volume Ratio (S/V)
- small size may be protective mechanism from predation
16
Q
Bacterial Cell Organization
A
Cell envelope
Cytoplasm
External Structures
17
Q
Layers of the Bacterial Envelope
A
Plasma Membrane
Cell Wall
Layers outside the cell wall
18
Q
thin barrier that surrounds the cell and separated the cytoplasm from the cell’s environment
A
Bacterial Plasma Membrane
19
Q
gatekeeper for substances that enter and exit the cell
A
Bacterial Plasma Membrane
20
Q
Plasma Membrane is composed of amphiphatic lipids —
A
a. polar ends (hydrophilic)
b. non-polar tails (hydrophobic)
21
Q
Peripheral proteins are
A
loosely connected to membrane; easily removed
22
Q
Integral Proteins function
A
transport nutrients;
detector and pumps Hydrogen to generate ATP
23
Q
Selectively permeable membrane
A
Plasma membrane
24
Q
what molecules does plasma membrane selects to pass through
A
Small, neutral molecules
25
Cell Wall Functions
a. Confers shape and rigidity on the cell
b. Helps protect cell from osmotic lysis
c. Helps protect from toxic materials
d. May contribute to pathogenicity
26
Integrity of Gram + and Gram -: Hopanoid: Mycoplasma:
Sterol
27
rigid structure that lies just outside the cell plasma membrane
Peptidoglycan (murein)
28
stain purple; thick peptidoglycan
Gram positive
29
stain pink or red; thin peptidoglycan and outer membrane
Gram-negative
30
Peptidoglycan composed of two sugar derivatives called
N-acetylglucosamine
N-acetylmuramic acid
31
TRUE OR FALSE:
Peptidoglycan strands have a helical shape
TRUE
32
TRUE OR FALSE:
Peptidoglycan chains are cross-linked by peptides for strength
TRUE
33
interconnected networks
peptidoglycan sacs
34
TRUE OR FALSE:
Gram-positive cell walls does not contain teichoic acids (negatively charged).
FALSE, ‘cause they have them to maintain cell envelope, protect the cell from enviro substances and may be used to bind to host cells.
35
capsules and slime layers and S layer
Glycocalyx
36
Aid in attachment to solid surfaces
E.g., Biofilms in plants and animals
37
usually composed of polysaccharides; well-organized and not easily removed from cell; resistant to phagocytosis and protect cell from desiccation
CAPSULES
38
similar to capsules except diffuse, unorganized and easily removed; they may also aid in motility
Slime Layers
39
regularly structured layers of protein or glycoprotein that self-assemble
S-Layer
40
Gram-Negative: Outer membrane: Gram-Positive:
Peptidoglycan surface
41
S Layer Functions
A. Protect from Ion and pH fluctuations, osmotic stress, enzymes and predation
B. Maintains shape and rigidity
C. Promotes adhesion to surfaces
D. Protects from host defenses
E. Potential use in nanotechnology
42
Bacterial Cytoplasmic Structure
Cytoskeleton
Intracytoplasmic membranes
Inclusions
Ribosomes
Nucleoid and plasmids
43
Not common to all Bacteria (Cytoplasmic Structures)
Cytoskeleton
Plasmids
Intracytoplasmic membranes
44
plasma membrane and everything within
Protoplast
45
material bounded by the plasmid membrane
Cytoplasm
46
Homologs of all 3 eukaryotic cytoskeletal elements
Tubulin Homologues
Actin Homologues
Intermediate Filament
47
Tubulin Homologues
FtsZ - crosswalls
BtubA/BtubB - Stalk (Prosthecobacter spp.)
TubZ - encode by large plasmids
48
many bacteria; forms ring during septum formation in cell division
FtsZ
49
many rods; maintains shape by positioning peptidoglycan synthesis machinery
MreB
50
rare, maintains curve shape
CreS
51
observed in many photosynthetic bacteria and those with high respiratory activity
Plasma Membrane infoldings
52
organelle site of anaerobic ammonia oxidation
Anammoxosome in Plantomycetes
53
granules of organic and inorganic material that are stockpiled by the cell for future use
Inclusions (Phosphate and amino acids)
54
may be referred to as microcompartments
Inclusions
55
Storage of nutrients, metabolic end products, energy, building blocks
Storage Inclusions
56
Storage Inclusions
a. Glycogen storage
b. Carbon storage (poly-Beta-hydroxybutyrate (PHB)
c. Phosphate - Polyphosphate (Volutin)
d. Amino acids - cyanophycin granules
57
Cyanobacter has _______________, which a CO2 fixing bacteria
Carboxysomes
58
What does carboxysome contain for CO2 fixation?
Rubulose-1,5,-biphosphate carboxylase (Rubisco)
59
Found in aquatic, photosynthetic bacteria and archaea like Planktons; they provide buoyancy in gas vesicles
GAS VACUOLES
60
found in aquatic bacteria; magnetite particles for orientation in Earth’s magnetic field
MAGNETOSOMES
61
Helps form magnetosome chain
Cytoskeletal protein MamK
62
site of protein synthesis
RIBOSOMES
63
The S=Svedburg unit refers to the
Sedimentation Rate
64
Bacterial and Archaea ribosome
70S
(It is not exactly 80S because it overlaps)
65
Location of chromosome and associated proteins
Nucleoid
66
Closed circular, double-stranded DNA molecule
Plasmid
67
Supercoiling and nucleoid proteins aid in folding
Histone-like
68
Importance of Lipopolysaccharides
- contributes to negative charge on cell surface
- helps stabilize outer membrane structure
- may contribute to attachment to surfaces and biofilm formation
- creates a permeability barrier
- protection from host defenses (O antigen)
- can act as an edotoxin (lipid A)
69
TRUE OR FALSE:
Gram-negative outer membrane is more permeable than plasma membrane due to presence of porin proteins and transporter proteins
TRUE
70
form channels to let small molecules (600-700 daltons) pass
PORIN PROTEINS
71
TRUE OR FALSE:
Gram stain reaction was due to nature of cell wall
TRUE
72
How does the loss of crystal violet during decoloration step prevented?
It is due to the constriction, wherein the pores of peptidoglycan of the Gram-positive layer shrinks
73
Solute concentration outside the cell is less than inside the cell; water moves into cell and cell swells
Hypotonic environment
74
solute concentration outside the cell is greater than inside; water leaves the cell and plasmolysis occurs
HYPERTONIC ENVIRONMENT
75
Evidence of Protective Nature of the Cell Wall
It breaks the bond between N-acetylglucosamine and N-acetylmuramic acid
Lysozyme
76
Evidence of Protective Nature of the Cell Wall
Inhibits peptidoglycan synthesis
Penicillin
77
Cells that lose a Cell Wall May Survive in Isotonic Environments
- Protoplast
- Spheroplasts
- Mycoplasma
( Plasma Membrane is more resistant to osmotic pressure)
78
exist and replicate independently of chromosome
plasmids
79
may integrate into chromosome
episomes
80
contain few genes that are non-essential; confer selective advantage to host (e.g., drug resistant, pathogenecity)
Plasmid
81
Transfer of DNA from one cell to another
Conjugative Plasmid
82
carry antibiotic-resistance genes
R-plasmids
83
Production of antibiotics
Col Plasmids
84
Carry genes that cause diseases
Virulence Plasmids
85
Synthesis of enzymes
Metabolic Plasmids
86
presence or absence of oxygen
Facultative anaerobes
87
Extend beyond the cell envelope in bacteria; Function in protection, attachment to surfaces, horizontal gene transfer, cell movement
Pili and Fimbriae and Flagella
88
short, thin, hairlike, proteinaceous appendages (up to 1000/cell)
Fimbriae; pili
89
can mediate attachment to surfaces, motility, DNA uptake
Fimbriae; pili
90
longer, thicker, and leas numerous (1-10/cell); genes for formation found on plasmids; required for conjugation
SEX PILI
91
Threadlike, locomotor appendages extending outward from plasma membrane and cell wall
Flagella
92
Functions of flagella
motility and swarming behavior
attachment to surfaces
may be virulence factors
93
Thin, rigid protein structures that cannot be observed with bright-field microscope unless specially stained
BACTERIAL FLAGELLA
94
one flagellum
Monotrichous
95
Flagellum at end of cell
Polar flagellum
96
One flagellum at each end of cell
Amphitrichous
97
Cluster of flagella at one or both ends
Lopotrichous
98
flagella all over the cell surface
Peritrichous
99
Three parts of Flagella
Filament, Hook, and Basal body
100
extends from cell surface to the tip; hollow, rigid cylinder of flagellin protein
FILAMENT
101
links filament to basal body
HOOK
102
series of rings that drive flagellar motor
Basal body
103
filament subunits self-assemble with help of filament cap at
TIP, NOT BASE
104
Movement due to chemicals
CHEMOTAXIS
105
Move toward chemical attractants such as nutrients
POSITIVE CHARGE
106
Movement away of from harmful substances
NEGATIVE CHARGE
107
Movement in response to temperature, light, oxygen, osmotic pressure, and gravity
MOTILITY
108
Flagellum rotates like a propeller; CCW=Forward and CW=Tumble
FLAGELLAR MOVEMENT
109
- C (FliG protein) ring and MS ring turn and interact with stator
ROTOR
110
MotA and MotB proteins; form channel through plasma membrane
STATOR
111
TRUE OR FALSE:
Protons move through MotA and MotB channels using energy proton motive force
TRUE
112
powers rotation of the basal body and filament
TORQUE
113
Corkscrew shape exhibits flexing and spinning movements
SPIROCHETE MOTILITY
114
may involve Type IV pili and slime; short, intermittent, jerky motions
TWITCHING MOTILITY
115
smooth movements
GLIDING MOTILITY
116
Movement toward a chemical attractant or away from a chemical repellent
CHEMOTAXIS
117
negative stimuli
TUMBLE
118
No attractant present
Random movement Forward run
119
Attractant present
Directed movement
120
Moving towards the source of light
Phototaxis
121
Complex, dormant structure formed by some bacteria; resistant to heat, radiation, chemicals, dessication
Bacterial Endospore
122
spore surrounded by thin covering
EXOSPORIUM
123
What makes an Endospore so resistant?
-Calcium (Complex with dipicolinic acid)
-Small, acid-soluble, DNA-binding proteins (SASPs)
-Dehydrated core
-spore coat and exosporium protect
124
process of endospore formation
SPORULATION
125
Sporulation Process
1. Inward folding
2. Septum formation
3. Engulfment
4. Cortex Formation
5. Coat Synthesis
6. Completion; Increase in refractility and heat resistance
7. Lysis
126
Prepares spores for germination
activation
127
Spore swelling and rupture of absorption of spore coat
GERMINATION
128
emergence of vegetative cell
outgrowth
