Viruses_Bacteria_Archaea_B Flashcards
2 Prokaryote Domians
Bacteria
Archaea
Leeuwenhoek
discovered bacteria in the 17th century
examined scrapings from teeth
thought “little animals” arose spontaneously
Pasteur
experiment disproved spontaneous generation around 1850
crooked neck showed particles settle from outside
Prokaryote Size
1 - 10 um in length
.7 - 1.5 um in width
some variety
prokaryote greek
before a nucleus
how far do prokaryotic fossils date back
3.5 - 3.8 billion years
how long do fossils indicate prokaryotes lived alone
2 billion years
why can Prokaryotes thrive in variety of environments
variety of ways to obtain energy
glycocalyx
organized capsule that surrounds cell wall
slime layer
loose gelatinous sheath that surrounds cell wall
outer layer that protects parasitic prokaryote cell from host defenses
glycocalyx/ slime layer
flagella 3 parts
basal body
hook
filament
fimbriae
enable prokaryotes to adhere to surfaces
short hairlike filaments on surface
disease from Neisseria gonorrhoeae
fimbriae allow N. gonorrhoeae to attach to host cells and cause gonorrhea
nucleoid
single circular strand of DNA, dense area in prokaryotes of chromosome location
plasmids
accessory rings of DNA
found in some prokaryotes
prokaryote ribosomes
protein synthesis
smaller than eukaryotic ribosomes
binary fission overview
prokaryote form of replication
splitting of parent cell into 2 daughter cells
binary fission steps
1) singular circular chromosome replicates; 2 copies separate as cell enlarges
2) plasma membrane/cell wall separate the cell into 2 cells
Prokaryote Reproduction Methods
Genetic Recombination:
- conjugation
- transformation
- transduction
conjugation
DNA passed between bacteria through sex pilus
transformation
ingest free peices of DNA from other dead/alive bacteria
transduction
bacteriophages transfer DNA from one cell to another
what do i need for the quiz
2 pencil
Kingdom for Domain Bacteria
Eubacteria
number of species of Eubacteria
tens of millions
number of Eubacteria species named
9000
most common type of prokaryote
Bacteria
peptidoglycan
located outside plasma membrane
rigid cell wall
complex of polysaccharides linked by amino acids that keeps the cell from exploding/collapsing during osmosis
Gram Positive
purple
thick peptidoglycan
Gram Negative
pink
thin peptidoglycan
when Gram stain procedure developed
late 1880s
developed by Hans Christian Gram
Bacteria three basic shapes
spirillum: spiral-shaped
bacillus: elongated/rod-shaped
coccus: spherical
Obligate anaerobes
toxic to O2
grow in absence of O2
Health effects of anaerobic bacteria
botulism, gas gangrene, tetanus
facultative anaerobes
able to grow with or without O2
Aerobic
require O2. All multi-cellular organisms are aerobic
Autotrophic Bacteria
generate own food from inorganic compounds
Photoautotrophs
use light energy to assemble required organic molecules
Chemoautotrophs
generate organic molecules from oxidation of inorganic compounds
Source of energy besides Sun
deep ocean hydrothermal vents
provide H2S for chemosynthesis
Methanogens
methane producing chemosynthetic bacteria from hydrogen gas and CO2
Rhizobium
symbiotic between legume plants and bacteria (mutualism)
nodules formed on plant roots
Bacteria provide plants with Nitrogen
Plants give protection and nutrients
Heterotrophic bacteria
can’t make own food
Chemoheterotrophs
ingest pre-formed organic nutrients
sapotrophs
break-down decaying organic matter
chemicals we utilize produced by Bacteria
ethyl alcohol, acetic acid, butyl alcohol, acetones
more chemicals we utilize produced by Bacteria
butter, cheese, sauerkraout, rubber, cotton, silk, coffee, and cocoa
antibiotics
Symbiosis
close association between 2 or more different species
mutualism
both species benefit
commensalism
1 species benefits, other is unaffected
parasitism
one species benefits, other is harmed
Formed in response to harmful environmental conditions
endospores
T/F endospores can survive boiling, freezing hydration, and UV
true
vegetative cells (endospores)
endospores absorb water and grow again?
Bacterial Toxin release sources
secreted by living cell
released by portions of cell wall when bacteria die
what normally causes bacterial disease
toxins
Shigella dysentariae
releases a toxin
sticks to the intestine
causes diarrhea
Clostridium tetani
causes all muscles to stiffen
ingest spores
disease comes from toxins
Clostridium botulinum
ingest spores
disease comes from toxins
babies can die from this
Babies do not have stomach acids and pH that breaks down these spores
Bacillus anthracis
Anthrax
transferred as spores
Antibiotic pathways
inhibit
- protein synthesis
- cell wall synthesis
- nucleic acid synthesis
Cyanobacteria - blue-green algae charectrestics
Prokaryotic, not algae
can be unicellular, colonial, filamentous
photosynthesis (first on earth)
heterocysts allow Nitrogen fixation
where are cyanobacteria commonly found
fresh water, soil, harsh habitats, moist surfaces
symbiotic cyanobacteria
liverworts, corals, ferns, and lichens
Cyanobacteria “bloom”
nitrates and phosphate cause blooms
die off
decomposing bacteria utilize oxygen
massive fish kills
Archaea Kingdom
Archaea
T/F rRNA base sequence different in Archaea than Bacteria
T
Methanogens
obligate anaerobes
live in marshes, swamps, intestinal tracts
produce methane as product of respiration
methane is greenhouse gas
what do halophiles remove excess of from inside cell
Chlorine
what temperature do thermophiles survive best above
80 degrees C
T/F there are thermophiles can live above boiling point
true
what pH do thermophiles grow best at
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