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Test 1 Flashcards

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1
Q

Biofilm

A

community of microO working together

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2
Q

16S rRNA Genes

A

Used to create 3 domain classification, small ribosomal subunit

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3
Q

Microbiologists study…

A

Cellular, ie fungi, protists, bacteria, archaea

Acellular, ie viruses, viroids, virusoids, prions

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4
Q

We will study…

A

Bacteria, Archaea, Viruses, Viroids, Virusoids, Prions

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5
Q

Microbiology prompted creation of…

A

immunology

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6
Q

Antony van Leeuwenhoek (1632-1723)

A

First person to observe and describe microO accurately, aided in development of microscope

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7
Q

Spontaneous generation

A

living organisms can develop from nonliving or decomposing matter, popular up to 1600s

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8
Q

Francesco Redi (1626-1697)

A

disproved spontaneous generation for large animals, maggots on decaying meats from fly eggs

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9
Q

John Needham (1713-1781)

A

mutton broth -> boiled -> sealed = microO

concluded -> “vital force”

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10
Q

Lazzaro Spallanzani (1729-1799)

A

broth -> sealed -> boiled = no microO
concluded -> air carries germs
BUT maybe air supports life

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11
Q

Louis Pasteur (1822-1895)

A

Nutrient soln in flasks w/ curved necks -> boiled -> exposed to air
Disproved spontaneous generation

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12
Q

John Tyndall (1820-1893)

A

dust carries microO, sterile broth -> one neck of flask broken, other not -> broken neck growth occurs

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13
Q

Microbes causative in disease?

A

diverse evidence:
1) Agostini Bassi (1773-1856)
• disease of silkworms was caused by a fungus
2) M. J. Berkeley (ca. 1845)
• Great Potato Blight of Ireland caused by a fungus
3) Heinrich de Bary (1853)
• smut and rust fungi => cereal crop diseases
4) Louis Pasteur
• silkworm disease caused by a protozoan

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14
Q

Joesph Lister (1827-1912)

A

indirect evidence for microO cause of disease, antiseptic surgical techniques, heat sterilization/phenol lessen # infections

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15
Q

Thomas Eakins

A

Gross Clinic Painting

Agnew Clinic

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16
Q

Robert Koch (1843-1910)

A

est. relationship between B. anthracis and anthrax; used criteria developed by Jacob Henle:
injected healthy w/ material from sick
sick spleen into culture
spores into healthy mice

Now known as Koch’s Postulates

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17
Q

Koch’s Postulates

A

To prove a causal relationship between microorg. & disease:

  1. The microorganism must be present in every case of the disease but absent from healthy individuals
  2. The suspected microorganism must be isolated and grown in a pure culture
  3. The same disease must result when the isolated microorganism is inoculated into a healthy host
  4. The same microorganism must be isolated again from the diseased host
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18
Q

Koch’s work led to…

A

agar, petri dish, nutrient broth and agar, methods for isolating microO

Increased understanding of pathogens

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19
Q

Edward Jenner (~1798)

A

vaccination procedure to protect individuals from smallpox, preceded work est. role of microO in disease

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20
Q

Pasteur and Roux

A

incubation of cultures for long intervals, pathogens lost ability to cause disease “attenuated”
Transfer to healthy host protection against infection

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21
Q

Pasteur and coworkers

A

vaccines for chicken cholera, anthrax, and rabies

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22
Q

Emil von Behring (1854-1917) and Shibasaburo Kitasato (1852-1931)

A

Inactivated diphtheria toxin into rabbits, produced transferable antitoxin
developed antitoxins for diphtheria and tetanus
evidence for immunity from “soluble substances” in blood (humoral immunity)

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23
Q

Elie Metchnikoff (1845-1916)

A

discovered bacteria-engulfing, phagocytic cells in the blood, (cellular immunity)

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24
Q

Sergei Winogradsky (1856-1953) and Martinus Beijerinck (1851-1931)

A

pioneered use of enrichment cultures, selective media
soil microO
numerous interesting metabolic processes

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25
Microbiology as a basic science...
basic biology of microO | understanding microO improved understanding of other Os
26
Microbiology as an applied science...
medical microbio, immunology, food and dairy microbio, pub health microbio, industrial microbio, agricultural microbio
27
Future of Micriobiology...
new and old infectious diseases, industrial processes, diversity and ecology, biofilms, genome analysis, microbes as model systems
28
Magnification
increases apparent size of specimen, calculated by multiplying magnification factors of lenses
29
Resolution
minimum distance that two objects can be separated from one another, and still be recognized as distinct objects rather than 1 larger "fuzzy" object
30
Increasing Resolution
oil: higher refractive index than air decreasing illumination wavelength focusing illumination light (condenser)
31
Illumination: Brightfield
Method of lighting the specimen from opposite the objective appears dark against a light background common method usually need staining
32
Illumination: Darkfield
illuminationof the specimen w/o projecting light directly into the objective used to examine specimens which cannot be distinguished from the background unstained, living
33
Fixation
preservation of internal and external structures organism is killed and firmly attached to microscope slide heat fixing and chemical fixing
34
Heat fixing
preserves overall morphology (not internal structures)
35
Chemical fixing
protects fine cellular substructure and morphology of larger, more delicate organisms
36
Dyes
make cell structures more visible increased contrast w/ background chromophore groups + ability to bind cells
37
Basic dyes
positively charged
38
Acidic dyes
negatively charged
39
simple staining
single staining agent frequently basic dyes crystal violet; methylene blue
40
Differential stains
divides microO into groups based on their staining properties gram stain acid-fast staining of specific structures
41
Gram Staining
``` most widely used Gm+, Gm- primary stain, crystal violet mordant, gram's iodine decolorization, etoh counterstain, safranin Gm+ Purple GM- Pink ```
42
Acid Fast staining
staining for members of genus Mycobacterium M. tuberculosis M. leprae high lipid content in cell walls
43
Negative Staining
visualize capsules, colorless against a stained background
44
Spore Staining
Double staining technique | bacterial endospore vs vegetative cell
45
Flagellar Staining
Mordant to increase thickness
46
Phase-contrast light microscopy
visualizing living cells | no stain
47
Transmission electron microscopy
Much like brightfield, electron stream opposite to specimen
48
Scanning electron microscopy
More like darkfield, visualize outside of specimen
49
cocci (s., coccus)
Spheres
50
diplococci (s., diplococcus)
Pairs
51
streptococci
Chains of spheres
52
staphylococci
grape-like clusters of spheres
53
tetrads
4 cocci in a square
54
sarcinae
cubic configuration of 8 cocci
55
bacilli (s., bacillus)
rods
56
coccobacilli
very short rods
57
vibrios
"comma" shaped
58
spirilla (s., spirillum)
rigid helices
59
spirochetes
flexible helices
60
filamentous
form hyphae
61
mycelium
branched hyphae
62
unusual shapes
archaea
63
Bacterial cell envelope
plasma membrane + surrounding layers
64
Bacterial plasma membrane
``` separation of cell from its environment selectively permeable crucial metabolic processes - respiration, lipid synthesis, (some) photosynthesis membrane receptors ex. phosphatidylenthanolamine + hopanol ```
65
Bacterial cell wall
``` shape protection may contribute to pathogenicity may protect from toxic substances Peptidoglycan aka murein ```
66
Periplasmic space
gap between plasma membrane and cell wall in Gm+ or between plasma membrane and OM in Gm- periplasmic + exoenzymes
67
Periplasmic enzymes
``` periplasm of Gm- nutrient aquisition electron transport peptidoglycan synthesis modification of toxic compounds ```
68
Exoenzymes
secreted by Gm+ bacteria | similar functions to periplasmic enzymes
69
Cell Wall and osmotic protection
osmotic lysis - hypertonic solns, cell wall protects | plasmolysis - hypertonic solns, cell wall can't protect
70
Bacterial cell wall and Gram staining
thought to involve constriction of the thick peptidoglycan layer of gram positive cells Thinner peptidoglycan layer of gram-negative bacteria does not prevent loss of crystal violet
71
Bacterial cell wall structure: peptidoglycan
polysaccharide formed from peptidoglycan subunits backbone: alternating N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) most Gm- walls z shaped bridge most Gm+ walls pentaglycine bridge Helical cross linking for strength
72
Gram-positive cell envelope
No OM Cell wall primarily peptidoglycan may also contain teichoic acids lipoteichoic acid anchors to PM Some Gm+ bacteria has layer of proteins on surface of peptidoglycan
73
Gram-negative cell envelope
OM: lipids, lipoproteins, and lipopolysaccharide (LPS) no teichoic acids cell wall: thin peptidoglycan layer surrounded by OM
74
Gm- cell envelope: Braun's lipoproteins
connect OM w/ peptidoglycan
75
Gm- cell envelope: adhesion sites
direct contact between plasma membrane and OM, may allow direct movement of material into cell
76
Gm- cell envelope: lipopolysaccharides (LPS)
O antigen: protection from host defenses, immunogenic core polysaccharide: contributes to negative charge on cell surface lipid A: helps stabilize OM structure, can act as an exotoxin
77
exotoxin
pathogenic when released, by death or cleavage
78
endotoxin
intact bacteria is pathogenic
79
Gm- cell envelope: OM
protective membrane more permeable than plasma membrane presence of porins and transporters
80
Layers outside the cell wall
``` Typically pathogenic have these Capsules, Slime Layers, S-layers protection from host defenses protection from harsh environmental conditions attachment to surfaces protection from viral infection or predation by bacteria protection from chemicals in environment motility protection against osmotic stress ```
81
Capsules
usually polysaccharides well organized; not easily removed resist phagocytosis
82
Slime layers
polysaccharides | diffuse, unorganized; easily removed
83
S-layers
structured layers of protein or glycoprotein | common in Archaea
84
glycocalyx
eukaryotes polysaccharide network like capsule/slime layer
85
Archaeal cell envelope
different from bacterial both molecularly and organizationally methanochondroitin = cell wall like pseudomurein
86
Archaeal Plasma membrane
composed of unique lipids some have monolayer some bilayer
87
Archaeal Cell Wall
Gm stain not useful | lack peptidoglycan
88
The cytoplasmic matrix
substance between membrane and nucleoid packed with ribosomes and inclusion bodies highly organized; cytoskeleton-like organization/function
89
Bacterial cytoskeleton
homologs of eukaryotic cytoskeleton components have been identified.
90
Tubulin homologs
FtsZ - cell division | BtubA/BtubB - unknown
91
Actin homologs
FtsA - cell division MamK - positioning magnetosomes MreB/Mbl - maintains cell shape, segregates chromosomes, localizes proteins
92
Intermediate Filament homologs
CreS (crescentin) - induces curvature in curved rods
93
Unique bacterial cytoskeletal proteins
MinD | ParA
94
Bacterial intracytoplasmic membranes
plasma membrane infoldings | anammoxosome
95
plasma membrane in-foldings
found in many photosynthetic bacteria, and bacteria with high respiratory activity may be aggregates of spherical vesicles, flattened vesicles, tubular membranes
96
anammoxosome
membrane-bound organelle anaerobic ammonia oxidation unique to Planctomycetes
97
inclusion
aggregation of organic or inorganic material storage inclusions microcompartments other inclusions
98
Storage Inclusions: Carbon
glycogen inclusions | poly-beta-hydroxybutyrate inclusions
99
Storage Inclusions: phosphate
polyphosphate granules
100
Storage Inclusions: sulfur
sulfur globules
101
Storage inclusions: nitrogen
Cyanophycin granules cyanobacteria large polypeptides not from ribosomes, equal quantities of arg and asp
102
Microcompartments: carboxysomes
function other than metabolic stockpile cyanobacteria, CO2 fixing Concentration of CO2; enzyme localization ribulose-1,5-bisphosphate carboxylase (RUBISCO) fixes carbon in calvin cycle
103
Other inclusions: gas vacuoles
some aquatic prokaryotes provides buoyancy aggregates of gas vesicles hollow cylindrical structures
104
Other inclusions: magnetosomes
contain iron | used to orient cells in magnetic fields
105
Prokaryotic Ribosomes
``` complexes of protein and RNA sites of protein synthesis associated w/ plasma membrane - secrete matrix ribosomes - internal smaller than eukaryotic ribosomes 70S = large 50s + small 30s ```
106
Nucleoid
aka nuclear body, chromatin body, nuclear region ~60% DNA 30% RNA 10% Protein location of chromosome, usually 1/cell often circular nucleoid proteins probably aid in folding, differ from histones
107
Plasmids
usually small, closed circular DNA extrachromosomal not required for growth and reproduction can be laterally transferred
108
External Structures: Fimbriae
short, thin, hairlike, proteinaceous appendages up to 1000/cell mediate attachment to surfaces type IV fimbriae: twitching motility in some bacteria
109
External structures: sex pili
similar to fimbriae except longer, thicker, and less numerous 1-10/cell required for mating
110
Bacterial flagella
used by most motile bacteria thin, rigid structures patterns of arrangement
111
polar
flagellum at end of cell
112
monotrichous
one flagellum
113
amphitrichous
one flagellum at each end of cell
114
lophotrichous
cluster of flagella at one or both ends
115
peritrichous
spread over entire surface of cell
116
Bacterial flagella: ultrastructure
filament hook basal body
117
Bacterial flagella: filament
hollow, rigid cylinder | flagellin subunits
118
Bacterial flagella: hook
links filament to basal body
119
Bacterial flagella: basal body
series of rings that drive flagellar motor
120
Bacterial flagella synthesis
self-assembly flagellin transported through hollow filament, similar to type III secretion growth from tip, not base
121
Bacterial flagella movement
``` flagellum rotates like a propeller CCW - forward motion (run) CW - disrupts run (tumble) Motor on bottom, bearings on top Powered by proton gradient from ETC MotA and MotB make channel to turn Exergonic rxn ```
122
Archaeal Flagella
``` Analogous function, different structure more than one flagellar subunit type not hollow; thinner hook/basal body rotation CCW pulls cell CW pushes cell ```
123
Motility
Flagellar Movement Spirochete motility Twitching motility Gliding motility
124
spirochete motility
periplamic axial fibrils (bundles of flagellum): flexing/spinning movement movement kind of like a screw
125
twitching motility
pili (type IV) involved | observed in groups of cells (contacting)
126
gliding motility
coasting along solid surfaces no known visible motility structure cyanobacteria, myxobacteria, etc Myxococcus xanthus gliding; polysaccaride secretion or adhesion complexes
127
Chemotaxis
movement towards a chemical attractant or away from a chemical repellant detected by cell surface receptors
128
Absence of chemoattractant
random movement | about same number of tumbles and runs
129
Present chemoattractant
directional movement caused by lowering the frequency of tumbles longer runs when chemoattractant sensed inc. in concentration when conc. stops inc. number of tumbles inc.
130
Bacterial Endospore
formed by some Gm+ bacteria | dormant; resistant to numerous environmental conditions
131
Spore positions
Central Subterminal Terminal Swollen sporangium
132
Spore Structure
exosporium (thin) spore coat (thick) impermiable; chem. resistance Cortex; peptidoglycan Core wall; derived from plasma membrane, surrounds protoplast Protoplast; nucleoids, ribosomes, inactive
133
What makes an endospore so resistant?
not totally understood, but... calcium (complexed with dipicolinic acid) small, acid soluble, DNA binding proteins (SASPs) dehydrated core spore coat DNA repair enzymes
134
Sporulation
``` commences when growth ceases, lack of nutrients complex multistage process 1. cell division 2. plasma membrane pinches off cell into two areas 3. cell dies 4. cortex forms 5. spore finishes 6. vegetative cell falls away ```
135
Transformation of spore to vegetative cell
1. activation; prepares spore for germination 2. germination; spore swelling, rupture/absorption of spore coat, loss of resistance, increased metabolic activity 3. Outgrowth; emergence of vegetative cell
136
Common Nutrient Requirements
Macroelements | Micronutrients
137
Macroelements
most cell dry weight: C H O N S P K+ Ca2+ Mg2+ Fe2+/3+ Required in relatively large amounts
138
Micronutrients
trace elements Mn Zn Co Mo Ni Cu enzyme cofactors often supplied in water or media components
139
Carbon, Hydrogen, Oxygen, electrons
need often satisfied together carbon source often provides H, O and electrons C/H/O: biosynthesis electrons: energy + reduction during biosynthesis
140
Autotrophs
CO2 sole or principal biosynthetic carbon source
141
Heterotrophs
reduced, preformed, organic molecules from other organisms
142
Phototrophs
light as energy source
143
Chemotrophs
oxidation of organic or inorganic compounds as energy source
144
Lithotrophs
electrons from reduced inorganic molecules
145
Organotrophs
electrons from organic molecules
146
Majority of microO studied...
photoautotrophs + chemoheterotrophs
147
Most pathogens...
chemoheterotrophs
148
Photoorganoheterotrophs
polluted lakes
149
Chemolithoautotrophs
oxidation of reduced inorganic compounds
150
Chemolithoheterotrophs
important in nutrient cycling in ecosystems
151
mixotroph
can use multiple metabolic strategies
152
Requirements for nitrogen, phosphorus, and sulfur
needed for synthesis of key molecules nitrogen; organic molecules, ammonia, nitrogen gas phosphorus; inorganic phosphate sulfur; sulfate via assimilatory sulfate reduction
153
Growth Factors
``` essential cell components; cells can't synthesize must be supplied by environment AA's purines and pyrimidines vitamins - enzyme cofactors ```
154
Growth-response assay
measure concentrations of growth factors in a preparation | comparison of known to std. curve
155
Industrial fermentation
production of vitamins by microO | vit B12, C
156
Uptake of nutrients
passive diffusion facilitated diffusion active transport iron uptake
157
Passive diffusion
High to low concentration non-polar molecules Water, O2 CO2
158
Facilitated diffusion
``` similar to passive, not E dependent, high to low conc. size of gradient impacts uptake rate Carrier molecules smaller conc. gradient required transport of glycerol, sugars, AA's more prominent in eukaryotic cells Carrier saturation effect ```
159
Active Transport
``` Against conc. gradient E dependent - ATP or proton motive force Conc. molecules inside of cell Requires carrier proteins (Carrier Sat. effect) ABC transporters group translocation ```
160
ATP Binding Cassette (ABC) transporters
conserved in all three domains pore: 2 TM domains, nucleotide binding domains (ATP) substrate binding protein; in periplasm, deliver molecule to transporter sugars AAs certain antibiotics
161
Group Translocation
molecules modified during transport, energy dependent ex. sugar phosphotransferase system (PTS) widely distributed in bacteria, many faculative anaerobes, not in most aerobes
162
Phosphoenolpyruvate: sugar phosphotransferase system (PTS)
transport of many carbohydrates | PEP phosphorylates enzyme 1 phosphorylates heat-stable protein (HPr) phosphorylates enzyme IIA, IIB, for transport
163
Energy for active transport
ATP hydrolysis | H+ gradients from electron transport; direct energy, indirect energy
164
H+ gradients: direct energy
``` lactose permease (symporter), facilitative diffusion Na/H+ exchanger (antiporter) ```
165
H+ gradients: indirect energy
Na+ symporter, indirectly powered by proton motive force Na from Na/H+ exchanger
166
Iron Uptake
ferric iron (Fe3+) insoluble; uptake difficult
167
siderophores
``` aid uptake of Fe3+ enterobactin secreted; complexes with Fe3+ complex transported In Gm- complex bound by receptor OM periplasm: either Fe3+ released or complex transported via ABC ```
168
Getting things through the Gm- OM
small molecules - generalized porins large molecules - specialized porins Specific carriers - iron uptake
169
Culture media
preparations that support growth can be liquid or solid solidify with agar
170
polar
flagellum at end of cell
171
monotrichous
one flagellum
172
amphitrichous
one flagellum at each end of cell
173
lophotrichous
cluster of flagella at one or both ends
174
peritrichous
spread over entire surface of cell
175
Bacterial flagella: ultrastructure
filament hook basal body
176
Biofilm
community of microO working together
177
Bacterial flagella: filament
hollow, rigid cylinder | flagellin subunits
178
Bacterial flagella: hook
links filament to basal body
179
Bacterial flagella: basal body
series of rings that drive flagellar motor
180
Biofilm
community of microO working together
181
Bacterial flagella synthesis
self-assembly flagellin transported through hollow filament, similar to type III secretion growth from tip, not base
182
Bacterial flagella movement
``` flagellum rotates like a propeller CCW - forward motion (run) CW - disrupts run (tumble) Motor on bottom, bearings on top Powered by proton gradient from ETC MotA and MotB make channel to turn Exergonic rxn ```
183
Archaeal Flagella
``` Analogous function, different structure more than one flagellar subunit type not hollow; thinner hook/basal body rotation CCW pulls cell CW pushes cell ```
184
Biofilm
community of microO working together
185
Motility
Flagellar Movement Spirochete motility Twitching motility Gliding motility
186
spirochete motility
periplamic axial fibrils (bundles of flagellum): flexing/spinning movement movement kind of like a screw
187
twitching motility
pili (type IV) involved | observed in groups of cells (contacting)
188
gliding motility
coasting along solid surfaces no known visible motility structure cyanobacteria, myxobacteria, etc Myxococcus xanthus gliding; polysaccaride secretion or adhesion complexes
189
Biofilm
community of microO working together
190
Chemotaxis
movement towards a chemical attractant or away from a chemical repellant detected by cell surface receptors
191
Absence of chemoattractant
random movement | about same number of tumbles and runs
192
Present chemoattractant
directional movement caused by lowering the frequency of tumbles longer runs when chemoattractant sensed inc. in concentration when conc. stops inc. number of tumbles inc.
193
Bacterial Endospore
formed by some Gm+ bacteria | dormant; resistant to numerous environmental conditions
194
Spore positions
Central Subterminal Terminal Swollen sporangium
195
Spore Structure
exosporium (thin) spore coat (thick) impermiable; chem. resistance Cortex; peptidoglycan Core wall; derived from plasma membrane, surrounds protoplast Protoplast; nucleoids, ribosomes, inactive
196
Biofilm
community of microO working together
197
What makes an endospore so resistant?
not totally understood, but... calcium (complexed with dipicolinic acid) small, acid soluble, DNA binding proteins (SASPs) dehydrated core spore coat DNA repair enzymes
198
Biofilm
community of microO working together
199
Sporulation
``` commences when growth ceases, lack of nutrients complex multistage process 1. cell division 2. plasma membrane pinches off cell into two areas 3. cell dies 4. cortex forms 5. spore finishes 6. vegetative cell falls away ```
200
Biofilm
community of microO working together
201
Transformation of spore to vegetative cell
1. activation; prepares spore for germination 2. germination; spore swelling, rupture/absorption of spore coat, loss of resistance, increased metabolic activity 3. Outgrowth; emergence of vegetative cell
202
Biofilm
community of microO working together
203
Common Nutrient Requirements
Macroelements | Micronutrients
204
Macroelements
most cell dry weight: C H O N S P K+ Ca2+ Mg2+ Fe2+/3+ Required in relatively large amounts
205
Micronutrients
trace elements Mn Zn Co Mo Ni Cu enzyme cofactors often supplied in water or media components
206
Biofilm
community of microO working together
207
Carbon, Hydrogen, Oxygen, electrons
need often satisfied together carbon source often provides H, O and electrons C/H/O: biosynthesis electrons: energy + reduction during biosynthesis
208
Autotrophs
CO2 sole or principal biosynthetic carbon source
209
Heterotrophs
reduced, preformed, organic molecules from other organisms
210
Phototrophs
light as energy source
211
Chemotrophs
oxidation of organic or inorganic compounds as energy source
212
Lithotrophs
electrons from reduced inorganic molecules
213
Organotrophs
electrons from organic molecules
214
Biofilm
community of microO working together
215
Majority of microO studied...
photoautotrophs + chemoheterotrophs
216
Most pathogens...
chemoheterotrophs
217
Photoorganoheterotrophs
polluted lakes
218
Chemolithoautotrophs
oxidation of reduced inorganic compounds
219
Chemolithoheterotrophs
important in nutrient cycling in ecosystems
220
mixotroph
can use multiple metabolic strategies
221
Requirements for nitrogen, phosphorus, and sulfur
needed for synthesis of key molecules nitrogen; organic molecules, ammonia, nitrogen gas phosphorus; inorganic phosphate sulfur; sulfate via assimilatory sulfate reduction
222
Growth Factors
``` essential cell components; cells can't synthesize must be supplied by environment AA's purines and pyrimidines vitamins - enzyme cofactors ```
223
Biofilm
community of microO working together
224
Growth-response assay
measure concentrations of growth factors in a preparation | comparison of known to std. curve
225
Industrial fermentation
production of vitamins by microO | vit B12, C
226
Uptake of nutrients
passive diffusion facilitated diffusion active transport iron uptake
227
Biofilm
community of microO working together
228
Passive diffusion
High to low concentration non-polar molecules Water, O2 CO2
229
Facilitated diffusion
``` similar to passive, not E dependent, high to low conc. size of gradient impacts uptake rate Carrier molecules smaller conc. gradient required transport of glycerol, sugars, AA's more prominent in eukaryotic cells ```
230
Biofilm
community of microO working together
231
Biofilm
community of microO working together
232
Active Transport
``` Against conc. gradient E dependent - ATP or proton motive force Conc. molecules inside of cell Requires carrier proteins (Carrier Sat. effect) ABC transporters group translocation ```
233
ATP Binding Cassette (ABC) transporters
conserved in all three domains pore: 2 TM domains, nucleotide binding domains (ATP) substrate binding protein; in periplasm, deliver molecule to transporter sugars AAs certain antibiotics
234
Group Translocation
molecules modified during transport, energy dependent ex. sugar phosphotransferase system (PTS) widely distributed in bacteria, many faculative anaerobes, not in most aerobes
235
Phosphoenolpyruvate: sugar phosphotransferase system (PTS)
transport of many carbohydrates | PEP phosphorylates enzyme 1 phosphorylates heat-stable protein (HPr) phosphorylates enzyme IIA, IIB, for transport
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Biofilm
community of microO working together
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Energy for active transport
ATP hydrolysis | H+ gradients from electron transport; direct energy, indirect energy
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H+ gradients: direct energy
``` lactose permease (symporter), facilitative diffusion Na/H+ exchanger (antiporter) ```
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H+ gradients: indirect energy
Na+ symporter, indirectly powered by proton motive force Na from Na/H+ exchanger
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Biofilm
community of microO working together
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Iron Uptake
ferric iron (Fe3+) insoluble; uptake difficult
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siderophores
``` aid uptake of Fe3+ enterobactin secreted; complexes with Fe3+ complex transported In Gm- complex bound by receptor OM periplasm: either Fe3+ released or complex transported via ABC ```
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Biofilm
community of microO working together
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Getting things through the Gm- OM
small molecules - generalized porins large molecules - specialized porins Specific carriers - iron uptake
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Culture media
preparations that support growth can be liquid or solid solidify with agar
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Biofilm
community of microO working together
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Defined (synthetic) media
components/concentrations known controlled growth environment can be used for certain bacteria that are known well
248
Complex media
contain some ingredients of unknown composition and/or concentration Peptones - protein hydrolysates from partial digestion of various proteins extracts - aqueous; beef or yeast agar (solidify liquid medium) - sulfated polysaccharide
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Selective media
favors growth of some microO; inhibits others | ex. MacConkey agar selects for Gm- bacteria
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Differential media
distinguish between different groups of microO based on their biological characteristics ex. blood agar - hemolytic vs nonhemolytic ex. MacConkey agar - lactose fermenters vs nonfermenters
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Blood agar
enriched and differential | hemolytic alpha and beta vs nonhemolytic
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MacConkey agar
selective and differential | inhibit growth of Gm+, Gm- with acidic products red
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Spread plate technique
best for less dense culture
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Streak plate technique
best for very dense culture
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Pour plate technique
sample diluted, serial dilutions | most control, can determine number of bacteria in original culture
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Colony Morphology and Growth
growth most rapid at colony edge | biofilms on surfaces in nature

Microbiology (4 decks)

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