Lecture 1A : Introduction to Microbial Physiology and Prokaryotic Cell Structures Flashcards
(114 cards)
1
Q
What is microbial Physiology?
A
Study of cell functions
2
Q
Which is included in the study of microbial physiology?
A
- Microbial growth
- Microbial metabolism
- Microbial cell structure
3
Q
Microbial physiology is “___”
A
Structure-function relationships in microorganisms, especially how microbes respond to their environment
4
Q
The focus of OUR microbial physiology
A
Bacteria, particularly gram-negative bacteria such as Escherichia coli
5
Q
Major morphologies of prokaryotic cells
A
- Coccus
- rod/bacillus
- sprillum
6
Q
spherical or ovoid
A
coccus
7
Q
Cylindrical
A
spirillum
8
Q
curved or spiral
A
spirillum
9
Q
Morphology typically DOES NOT predict…..?
A
- Physiology
- ecology
- phylogeny
- other properties of a prokaryotic cell
10
Q
The size range for prokaryotes
A
0.2 µm to >700 µm in diameter
11
Q
Examples of very large prokaryotes
A
- Epulopiscium fishelsoni (Italicized)
- Thiomargarita namibiensis
12
Q
Size range for eukaryotic cells
A
2 to >600 µm in diameter
13
Q
Advantages of being small
A
- More surface area to cell volume
- greater nutrients and waste product exchange
- tend to grow faster
- mutations
- eukaryotic cells adapt slower
14
Q
Cellular organisms ___ µm in diameter are unlikely.
A
<0.15
14
Q
why is lower than <0.15 µm in diameter is unlikely?
A
- need volume to house proteins, nucleic acids, ribosomes etc
15
Q
Open oceans tend to contain small cells (0.2–0.4 µm in
diameter) known as ____
A
Ultramicrobacteria
16
Q
Genomes are highly streamlined, missing functions that must be supplied by other microbes or hosts (plants and animals).
A
Ultramicrobacteria
17
Q
Relationship between minimum size and environment
A
- Dictates the degree of interaction between inside and outside
- affect two important parameters that are related
- Cells of a given type maintain a characteristic cell size to function efficiently
17
Q
Microorganism that are an example of the size-environment relationship
A
Verrumicorbiales
Nanobacteria
18
Q
New isolates that grow well and maintain small cell size under relatively high nutrient growth conditions
A
Verrucomicorbiales
19
Q
a gram negative bacteria, and abundant within the environment.
A
verrucomicorbiales
20
Q
dwell (and are cultivated) in a relatively nutrient-rich environment, yet maintain their small cell dimensions
A
Nanobacteria
20
Q
General structure of cytoplasmic membrane
A
Phospholipid bilayer containing embedded proteins
- contains hydrophobic/philic
20
Q
Size of the bacterial cytoplasmic membrane
A
8-10 nm
21
Sterol-like molecules
Hopanoids
22
Main function of hopanoids
Helps with the integrity of the brain
22
The linkage that conect fatty acid to glycerol
ester linkage
23
Linkage present in bacteria
ester
23
Linkage that is present in archea
Ether
24
ether is only present in
archea
25
Archeal lipids have ___ instead of fatty acids
isoprenes
26
Major lipids in archeal membrane
- Phosphoglycerol with phytanyl
- diphosphoglyceron tetraethers with biphytanyl
27
The function of Cytoplasmic membrane
- Permeability barrier
- Protein anchor
- energy conservation and consumption
28
- Polar and charged molecules must be transported.
- Transport proteins accumulate solutes against the concentration gradient.
Permability barrier
29
holds transport proteins in place
Protein anchor
30
generation of proton motive force
energy conservation and consumption
31
The Bacterial Cell Walls
Peptidoglycan
32
Species of bacteria is seperated into two groups based on ____ ____
Gram stain
33
Gram-negative cell wall
two layers
- LPS
- Peptidoglycan
34
Gram-positive cell wall
thicker (primarily one layer of peptidoglycan)
35
rigid layer that provides strength
peptidoglycan
36
Components of peptidoglycan
- Alternating modified glucose
- amino cids
- cross-linked
37
The alternating modified glucose in peptidoglycan
NAG and NAM
38
NAG
N-acetylglucosamine
39
NAM
N-acetylmuramic acid
40
location of NAG and NAM linkage
Beta-1,4 linkages
41
the enzyme that can break peptidoglycan, by cleaving bonds between sugar
Lysozyme
42
Number of peptidoglycan in a gram-positive cell wall
up to 190
43
gram-positive cell wall commonly have ____
Teichoic acids
44
Acidic substances, covalently bound to peptidoglycan
Techoic acids
45
teichoic acids covalently bound to
membrane lipids
Lipoteichoic acids
46
Few prokaryotes that lacks cell walls
- mycoplasmas
- themoplasma
47
group of pathogenic bacteria related to gram-positives
mycoplasmas
48
The Outer Membrane
Lipopolysaccharide (LPS)
49
Components of LPS
- core poly
- O-specific-poly
- Lipid A
50
LPS is a barrier against??
Antibiotics and other harmful agents
51
LPS replaces most of ____ in the outer half of outer membrane
Phospholipids
52
Lipid A, the toxic component of LPS, not released by the cell
Endotoxin (Lipid A)
53
space located between cytoplasmic and outer membranes
- houses many extracelluar proteins
Periplasm
54
size of periplasm
approx. 15 nm wide
55
transmembrane protein channels for entrance and exit of solutes
Porins
56
The archeal cell walls have no ____ but _____
- no peptidoglycan
- pseudomurein
57
* found in cell walls of certain methanogenic Archaea
* polysaccharide similar to peptidoglycan
Pseudomurein
58
components of pseudomurein
- NAG and NAT
59
NAG
N-Acetylglucosamine
60
NAT
N-acetyltalosaminuronic acid
61
glycosidic bonds of pseudomurein
beta-1,3
62
___ and ___ cannot break pseudomurein
lysozyme and penicillin
63
Cells walls of some archaea lack pseudomurein so they contain ___ ____ ___
other polysaccharide polymers
64
Polysaccharide polymers for archea that lacks pseudomurein
S-layers
65
- most common cell wall type (in Archaea)
- consist of protein or glycoprotein
- paracrystalline structure
- in many organisms, present in addition to other cell wall
components, usually polysaccharides
- always outermost layer
S-layers
66
not considered part of the cell because these do
not confer significant structural length
Capsules and slime layers
67
tightly attached, tight matrix
capsules
68
capsules is visible if treated with
India ink
69
loosely attached, easily deformed
Slime layer
70
How does capsule and slime layer cause virulence factors
protecs against phagocytosis of cells
71
functions of capsules and slime layers
- formation of biofilm
- attachment to surfaces
- virulence factors
- prevents dehydration/dessication
72
filamentous protein structures about 2-10nm wide
Fimbriae and pili
73
enable organisms to stick to surfaces or form pellicles
Fimbriae
74
thin sheets of cells on a liquid surface
pellicles
75
are typically longer and fewer (1 or a few) found per cell than fimbriae
Pili
76
types of pili
- conjugative/sex pili
- type IV pili
77
facilitates genetic exchange between cells
Conjugative/sex pili
78
adhere to host tissues and support twitching motility
Type IV pili
79
- Archaeal "grappling hooks"
- assist in surface attachement , forming piofilms structurally resemble type IV pili except for barbed terminus , which attaches cells to other
Hamus/hami
80
energy reserves, carbon reservoirs, and/or have special functions
Cell inclusions
81
cell inclusions is enclosed by
thin membrane
82
cell inclusions reduces
osmotic stress
83
a lipid polymer used as biodegradable plastic
Poly-beta-hydroxyburic acid (PHB)
84
Types of cell inclusions
- Polyphosphate granules
- Sulfur globules
- Carbonate minerals
- Magnetosomes
85
a inclusions that is phospho-related, inorganic phosphate
Polyphosphate granules
86
elemental sulfur found in periplasm , oxidized to sulfate
Sulfur granules
87
biomineralization of barium , strontium, and Mg
Carbonate materials
88
magnetic iron oxides ;allow well to undeg magrenotaxis
- migration along magnetic field lines
Magnetosomes
89
- confer bouyancy in planktonic cells
- gas-filled structures made of protein
Gas vesicles
90
shape of gas vesicles
Conical-shaped
91
Gas vesicles is impermeable to
Water and solutes
92
structure of gas vesicles
Two proteins (Gvp A and Gvp C)
93
Endospores is formed during
Sporulation or endosporulation
94
* Highly differentiated resistant to heat, harsh chemicals, and radiation
Endospores
95
Survival structures to endure unfavorable growth conditions
endospores
96
the bacterial life cycle where endospore is formed
dormant stage
97
Endospore is present only on?
Gram-positive bacteria
98
Types of endospore location
- terminal
- Subterminal
- Central
99
bulge at the end of the cell
Terminal endospores
100
endospore is almost in the middle
subterminal endospores
101
endspore is located at the center
central endospores
102
Steps of endospore formation and germination
- Activation (heated for several minutes at elevated but sublethal temp)
- Germination (rapid, in minutes, loss of resistance to heat and chemicals)
- outgrowth (swelling from water uptake, synthesis of RNA, proteins and DNA)
103
layers of endospores
- Exposporium
- Spore coat
- Core wall
- Cortex
- DNA
104
Endospore contains ____ acid
dipocolinic acid
105
sCore of endospores contains
- small acid-soluble spore proteins (SASP)
106
bind and protect DNA and function as carbon and energy source for outgrowth
SASP
107
causes the dryness of the spore
calcium DPA
108
NAT
N-acetyltalosaminuronic acid
