Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
32 Cards in this Set
- Front
- Back
|
TRUE
|
t or f:
every 1 cell= 10 microbial cells associated with it |
|
|
Proteobacteria
|
-divided into classes: alpha, beta, gamma, delta, zeta, epsilon
- all gram NEG -many medically/industrially important taxa |
|
|
Purple Phototrophic Bacteria
|
-facultative anaerobes
-perform anocygenic photosynthesis -contains bacteriochlorophylls (blue) & carotenoids (red) -intracellular photosynthetic membranes -incr light = many membranes? |
|
|
Purple Sulfur Bacteria
|
-use H2S as an electron donor for E for CO2 fixation
-S elemental is stored either intracellularly or extracellularly -found in stratified lakes (light &H2S) -all belong to class gammaproteobacteria |
|
|
Chemolithotrophy
(Sulfur and Iron Oxidizing Bacteria) |
-E is obtained by oxidation of reduced inorganic compounds; Fe2+, S=, So, S2O32-
-role in acid mine draining -divided by end product of S oxidation:Thiobacilli produces H2SO4 and Beggiatoa produces So |
|
|
Thiobacili
|
-betaproteobacteria
-may use pyrite (FeS2) as an electron source -production of H2SO4 (iron prospecting & acid mine drainage) -obligate autotrophs (CO2 fixation); carboxysome- Calvin Cycle enzymes |
|
|
Beggiatoa
|
-gammaproteobacteria
-large filaments with many So globules -salt marshes, sewage treatment, plant rhizosphere -historical perspective: formulation of chemolithotrophic concept -energy from sulfide oxid. and C from organic matter -myxotrophy -since they are not autotrophs, they dont need light |
|
|
Myxotrophy
|
chemolithoorganotrophy
|
|
|
Methane Monooxygenase
|
oxygenates methane to methanol; a strictly aerobic process
|
|
|
Methanotrophs & Methylotrophs
|
-membranes contain sterols (prokaryotic exception; along with wall-less mycoplasmas)
-methano: can us CH4 -methyl: can use other C1 compounds |
|
|
Prokaryotic exceptions
|
-membranes containing sterols
-wall-less mycoplasmas |
|
|
Methylotrophs (2 Types)
|
-type I: gammaproteobacteria; use ribulose monophosphate cycle to assimilat C1 compounds; disc shaped internal membranes; obligate C1 utilizers
-type II: alphaproteobacteria; use serine pathway for C1 assimilation; internal membranes positioned along periphery of cells; can use C-C containing organic compounds |
|
|
Type I Methylotroph
|
-gammaproteobacteria
-use ribulose monophosphate cycle to assimilar C1 -internal membranes are disc shaped -obligate C1 utilizers |
|
|
Type II Methylotroph
|
-alphaproteobacteria
-use serine pathway for C1 assimilation -internal membranes lined along periphery of cell -can use a C-C containing organic compounds |
|
|
Methanotrophs
|
-live in environments rich in methane and where oxygen is available; water column of stratified freshwater lakes
-symbionts of marine mussels facilitating animal growth on account of methane |
|
|
Pseudomonas
|
-degrade a large number of organic compounds and xenobiotics
-animal and plant pathogens- opportunists (can become pathogenic under certain circumstances) -gammaproteobacteria -curved rods with polar flagella, oxidase positive, no production of gas from glucose; use glucose by the entner-doudoroff pathway |
|
|
Chemoorganotrophs
|
-use organic material
-humans are an example |
|
|
Chemoorganotroph
(The Enteric Bacteria) |
-gammaproteobacteria that are closely related to each other
-nonsporulating; if motile, by peritrichous flagella; -oxidase NEG -facultative anaerobes -importance as pathogens of humans and animals; ex: escherichia coli |
|
|
Escherichia coli
|
-uses O2 and creates anoxic environment
-this is helpful because most of our GI microbes are strict anaerobes -vitamin k production -some pathogenic; diarrhea and UTI |
|
|
Salmonella and Shigella
|
very similar to E.coli based on DNA-DNA hybridization
-most strains pathogenic |
|
|
Salmonella
|
-typhoid fever
-gastroenteritis |
|
|
Shigella
|
bacillary dysentery
|
|
|
Vibrio, Aliivibrio, Photobacterium
|
-gammaproteobacteria
-facultative anaerobes -fermentative metabolism -motile -oxidase POS |
|
|
Bioluminescence
|
production of light by the enzyme luciferase that oxidizes long chain aldehydes to fatty acids in presence of O2
-rxn uses electrons from flavin mononucleotides to reduce O2 -in photobacterium and some vibrio spp |
|
|
Autoinduction
|
mechanism whereby transcription is induced when cell density reaches a critical concentration
|
|
|
Quorum Sensing
|
-similar to microbial luminescence
-regulation of gene expression in response to fluctuations in cell-population density -only beneficial when there are many? |
|
|
Gliding Myxobacteria
|
-deltaproteobacteria
-aerobic copiotroph (predator) -motion by gliding in the absence of flagella (slime layers) -culture forms fruiting bodies in response to starvation |
|
|
Firmicutes and mollicutes
|
-gram POS
-non spore formers -endospore formers -cell wall-less bacteria; cell rigidity with sterols (mollicutes) |
|
|
Cyanobacteria and Prochlorophytes
|
-oxygenic photosynthesis
-chlorophyll a and phycobilins |
|
|
Cyanobacteria
|
-gas vesicles for buoyancy
-heterocysts role in N2 fixation -thylakoids role in photosynthesis |
|
|
Cyanphycin
|
-N2 and energy storage
-production of ATP by argenine dehydrolase |
|
|
Prochlorophytes
|
oxygenic phototrophs that contail chlorophyll a and b and DO NOT contain phycobilins
|
