Lecture 5B - Functional Anatomy of Bacterial Cells Flashcards
1
Q
who published the first attempt to depict the common evolutionary history of all living cells
A
Ernst Haeckel
1866
2
Q
single celled organisms by Haeckel
A
Monera
3
Q
Best known for his discovery of Archaea
A
Carl Woese
4
Q
what was Carl Woese’ specific research interest as a professor in the University of Illinois Urbana-Champaigne?
A
refine Linnaean classification of organisms
5
Q
why is it said that Carl Woese rewrote the tree of life
A
discovery of Archaea
6
Q
why is the tree of life a phylogenetic tree
A
shows the evolution of relationships among different organisms
7
Q
three reasons why rRNA genes are suitable for pylogenetic analyses
A
- contains approximately 1500 bases, which is adequate (or sufficient) for analysis
- highly conserved and thus comparable between distantly related species
- contains variable regions, enabling comparison between closely related species
8
Q
Prokaryotic cells: DNA
A
- not enclosed with nuclear membrane
- single circular chormosome
- not associated with histone proteins
9
Q
Eukaryotic cells: DNA
A
- enclosed with nuclear membrane
- several linear chromosomes
- associated with histones and other proteins
10
Q
Prokaryotic cells: organelles
A
lack membrane-bound organelles
11
Q
Eukaryotic cells: organelles
A
membrane-bound
12
Q
Prokaryotic cells: cell wall
A
usually contain peptidoglycan, complex polysaccharide
13
Q
Prokaryotic cells: division
A
binary fission
14
Q
Eukaryotic cells: division
A
mitosis
15
Q
dimension of most bacterial cells:
diameter
A
0.2 to 2.0 µm
16
Q
diameter of human red bloock cells
A
7.5 to 10 µm
17
Q
dimension of most bacterial cells:
length
A
2 to 8 µm
18
Q
some cyanobacteria are up to __ long
A
60 µm
19
Q
bacterial cells have __ surface to volume ratios
A
large
20
Q
large surface to volume ratios, parts of cell
A
- close to surface
- can be quickly reached by nutrients
21
Q
human red blood cell in nm
A
10,000 nm
22
Q
plasma membrane of red blood cell in nm
A
10 nm
23
Q
Chlamydia size
A
1000 nm
24
Q
Ebola virus size
A
970 nm
25
E. coli size
3000 x 1000 nm
26
Bacteriophage T4 size
225 nm
27
Bacteriophage M13
800 x 10 nm
28
Tobacco mosaic virus size
250 x 18 nm
29
Vaccinia virus
300 x 200 x 100 nm
30
Adenovirus
90 nm
31
Bacteriphages f2, MS2
24 nm
32
Poliovirus
30 nm
33
Bacterial common cell shapes
1. Coccus
2. Bacillus
3. Spiral
34
spherical
coccus
35
Arrangement of cocci
1. diplococci
2. streptococci
3. tetrads
4. sarcinae
5. staphylococci
36
- pair of attached cocci
- remain attached after dividing
diplococci
37
chainlike arrangements
streptococci
38
- groups of four
- divide in two planes
tetrads
39
- groups of eight
- divide in three planes
sarcinae
40
- graplike clusters
- divide in multiple planes
staphylococci
41
- rod shaped
- some appear as single rods
bacillus
42
Different types of bacilli
1. single bacillus
2. diplobacilli
3. streptobacilli
4. coccobacillus
43
single rods
single bacillus
44
- pair of attached bacilli
- remain attached after dividing
diplobacilli
45
chainlike arrangement of bacilli
streptobacilli
46
- intermediate shape between coccus and bacillus
- oval rods
coccobacillus
47
have one or more twists
spiral
48
different types of spiral shaped bacteria
1. vibrio
2. spirillum
3. spirochete
48
- comma shaped cell
- look like curved rods
vibrio
49
- helical, corkscrew shaped bacteria with rigid bodies
- use whiplike external flagella to move
spirilla
50
what do spirilla shaped bacteria use to move
whiplike external flagella
51
- helical bacteria with flexible bodies
- use axial filaments (internal flagella) to move
spirochete
52
what do spirochete shaped bacteria use to move
axial filaments (internal flagella)
53
other less common bacterial shapes
1. star
2. flat and square
3. triangular
54
- have several possible shapes
- few in a few genera like Corynebacterium, Rhizobium
pleomorphic bacteria
54
few genera that are pleomorphic
- _Corynebacterium_
- _Rhizobium_
55
Structures external to the cell wall
1. glycocalyx
2. flagella
3. axial filaments (endoflagella)
4. fimbriae and pili
56
- glycocalyx made of sugar
- important in the formation of biofilm
extracellular polysaccharides (EPS)
57
several functions of glycocalyx
1. attachment to host cells
2. source of nutrition
3. prevent dehydration
4. escape host immune system
58
Two types of glycocalyx (sugar coat)
1. capsule
2. slime layer
59
organized polysaccharide substance that is firmly attached to the cell wall
capsule
60
anthrax bacteria can only cause anthrax if it has what
protein capsule
61
only __ with capsule can cause pneumonia
_Streptococcus_ _pneumoniae_
62
function of capsules
help bacteria escape host immune system by preventing destruction by phagocytosis
63
thin polysachharide substance that is loosely attached to the cell wall
slime layer
64
function of slime layer
- allow bacteria to adhere (teeth, rock surfaces, plant roots)
- help bacteria trap nutrients near cell
- prevent dehydration
65
long, thin, helical appendages
flagella
66
different flagella arrangements
1. monotrichous
2. amphitrichous
3. lophotrichous
4. peritrichous
67
single polar flagellum at one end
monotrichous
68
two polar flagella, one at each end
amphitrichous
69
two or more flagella at one or both ends
lophotrichous
70
many flagella over entire cell surface
peritrichous
71
what protein is flagella made up of
flagellin
72
three basic parts of flagella
1. filament
2. hook
3. basal body
73
- outermost region
- contains globular protein flagellin
- not covered by a sheath like eukaryotic filaments
filament
74
wider segment that anchors filament to basal body
hook
75
complex structure with a central rod surrounded by a set of rings
basal body
76
Gram-negative rings
2 pairs of rings (4 rings)
77
Gram-positive rings
1 pair of rings (2 rings)
78
movement of flagella
counterclockwise
79
Gram-negative rings
1. L ring
2. P ring
3. MS ring
4. C ring
80
L ring
lipopolysaccharide
81
P ring
peptidoglycan
82
MS ring
plasma membrane
83
C ring
cytoplasm
84
- the electrochemical potential difference of protons across a biological membrane
- allow flagellar movement
Proton motive force (PMF)
85
Gram-positive rings
1. MS ring
2. C ring
86
how do bacterial flagella move
rotation from basal body
87
Several patterns of bacterial motility
1. runs or swims
2. tumbles
88
bacterium moves in one direction
runs or swims
89
- bacterium changes direction
- caused by reversal of flagellar rotation
tumbles
90
movement of cell toward or away from a particular stimulus
taxis
91
Two types of taxis
1. chemotaxis
2. phototaxis
92
movement in response to a chemical stimulus
chemotaxis
93
movement in response to a light stimulus
phototaxis
94
towards nutrients
positive chemotaxis
95
away from repellant or toxic substance
negative chemotaxis
96
the movement of organisms towards or away from oxygen caused by changes in oxygen concentration
aerotaxis
97
forms a complex with the sensor kinase CheA and the coupling protein CheW
methyl-accepting chemotaxis protein (MCP)
98
methyl-accepting chemotaxis protein (MCP) forms a complex with the sensor kinase CheA and the coupling protein CheW triggers what
autophosphorylation which phosphorylate response regulators CheB and CheY
99
binds to flagellar motor switch
CheY-P
100
dephos-phorylates CheY-P
CheZ
101
continually adds methyl groups to the MCP
CheR
102
removes methyl groups from MCP
CheB-P (not CheB)
103
- can only be found in spiral bcteria
- corkscrew motion
axial filaments (endoflagella)
104
motion of axial filaments
corkscrew motion
105
examples of bacteria with axial filaments
1. _Treponema_ _pallidum_
2. _Leptospira_
3. _Borrelia_ _burgdorferi_
106
difference between _Mycoplasma_ and _Mycobacterium_
mycoplasma lack cell wall, have sterol
107
- also called “short attachment pili”
- attach to the host surface
- help bacteria colonise and cause infection
- present on the overall surface or concentrated towards the poles
Fimbriae
108
function of fimbriae
- attachment
- help form biofilm
- help adhere
108
- generally referred to as the appendages, which are involved in the conjugation
- also known as long conjugative pili
- longer than fimbriae
- involved in the cell to cell attachment during conjugation for DNA transfer
- facilitate gene transfer and recombination in the bacterial cell
- primitive mode of sexual reproduction in bacteria
Pili
109
function of pili
- conjugation (horizontal gene transfer)
- facilitate gene transfer and recombination
110
- prevents osmotic lysis
- maintains shape
- point of anchorage for basal bodies
- made of peptidoglycan (bacteria)
eubacterial cell wall
111
what does the cell wall prevent
osmotic lysis
112
major component of cell wall in bacteria (not archaea)
peptidoglycan
113
- Other term for peptidoglycan
- polymer of sugars and amino acids
murein
114
what does the peptidoglycan form
mesh-like layer
115
Each strand are two sugars linked alternatively
1. N-acetylglucosamine (NAG)
2. N-acetylmuramic acid (NAM)
116
how are NAG and NAM joined
beta-1,4 linkage
117
site where the peptidoglycn connects
- amino group
- carboxyl group
118
4 amino acids in peptidoglycan
1. L-Alanine
2. D-Glutamic acid
3. Diaminopimelic acid
4. D-Alanine
119
amino acid in Diaminopimelic acid of some bacteria
Lysine
120
Gram-negative cells that have thin cell walls, mostly have __ between peptide side chains
direct cross-links
121
Gram-positive cells that have thick cell walls, can also have peptide __ that extend between cross-linked peptide side chains
interbridges
122
example of interbridge
5 glycine interbridge
123
Gram-positive cell wall
1. thick peptidoglycan (many layers)
2. teichoic acids (makes wall like crosshairs)
124
Gram-negative cell wall
1. thin peptidoglycan
2. outer membrane
125
- passage of molecule in and out of cell
- embedded in outer membrane
porin protein
126
- surface-associated adhesion amphiphile from Gram-positive bacteria
- regulator of autolytic wall enzymes (muramidases)
Lipoteichoic acid (LTA)
127
teichoic acids
- alcohol and phosphate
- negative charge
128
- many layers of peptidoglycan
- teichoic acids
- may regulate movement of cations
Gram-positive cell walls
129
polysaccharide provide __ = __
antigenic variation = identification
130
Gram-positive cell walls produce what
exotoxins
131
Gram-positive cell walls are sensitive to what
- lysozyme
- penicillin
132
lysozyme
breaks bonds between NAMs and NAGs
133
penicillin
- targets peptidoglycan
- transpeptidation reaction
134
Two types of teichoic acid
1. glycerol phosphate / ribitol phosphate
2. attaches in glucose D-alanine
135
- thin layer of peptidoglycan and an outer membrane
- lipopolysaccharides
- LPS
- porins
Gram-negative cell wall
136
- evade phagocytosis and actions of immunity
- provide barrier to certain antibiotics and enzymes
Lipopolysaccharides (LPS)
137
- proteins that form channels
- makes CW also selectively permeable
porins
138
Where is Gram-negative cell wall sensitive
tetracycline
139
what does the Gram-negative cell wall produce
exotoxins
endotoxins
140
what does the outer membrane contain
- lipopolysaccharide
- phospholipids
141
structure of outer membrane
- outer leaflet
- inner leaflet
142
how does the outer membrane stay attached to the cell
anchored noncovalently to lipoprotein molecules (Braun's lipoprotein), which are covalently linked to peptidoglycan
143
lipoprotein that connects outer membrane to peptidoglycan
Murein lipoprotein or Braun's lipoprotein
144
what would happen if you targeted lipoprotein with antibiotics
outer membrane will be separated from cell
145
functions of outer membrane
1. defend against predators
2. extra barrier
3. creates compartment
4. produce toxin (lipid A)
5. fascilitates surface recognition
6. virulence factors
146
composition of lipopolysaccharide (LPS)
1. Lipid A
2. Core polysaccharide
3. O polysaccharide
147
- functions as an endotoxin
- responsible for symptoms associated with gram-infections
Lipid A
148
- attached to Lipid A
- provides stability
Core polysaccharide
149
- functions as an antigen
- useful in identification
O polysaccharide
150
microorganisms with unusual wall structures
1. _Mycobacterium_
2. _Mycoplasma_
3. Archaea
151
unusual wall structure of _Mycobacterium_
- Gram +
- mycolic acid
152
waxy to resist dehydration
mycolic acid
153
unusual wall structure of _Mycoplasma_
- smallest bacteria without CW
- have sterols in membrane (resist osmotic lysis)
154
unusual wall structure of Archaea
- no cell wall
- consists of pseudomurein (different carbohydrate)
