Transcript Microbe Diversity

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Bacteria (prokaryotes – no nucleus)
Archaea (prokaryotes, but with similarities to next
group)
Eukarya (eukaryotes – have DNA in a nucleus)
› Protista – single celled eukaryotes
 Many different ways of feeding and living
 Some are plant-like, some animal-like, and
some fungal-like
› Metazoans – multi-cellular eukaryotes
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Not cellular
› DNA or RNA genetic
material
› Inside a protein
coat
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Can’t reproduce on
own
Parasitic on cellular
organisms
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Infects host cell by
attaching to outer
surface
› Injects genetic
material
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Virus DNA/RNA takes
over host cell’s
metabolism to make
its own components
New virus parts made,
DNA/RNA replicated
Parts put together and
then the host cell is
lysed open
Note: host immune system has trouble finding the virus while it’s inside the host
cell.
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RNA viruses
› No error checking
when replicating
› Mutate quickly and so
vaccines must be
updated regularly
› Common cold
› Influenze can cause
worldwide epidemics
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DNA viruses
› Have error checking
enzymes when
replicate, so more
stable
› Small pox – vaccine
can give long term
protection
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Chicken pox
› One of 8 Herpes
viruses to infect
humans
› DNA virus
› Can lie dormant in
nerve cells for entire
life
› Shingles = virus reemerged later in life
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Transductional Virotherapy uses viruses that
recognize cell membrane receptors
specific to cancer cells.
› Virus attacks and multiplies in cancer cells only
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Transcriptional Virotherapy uses viruses that
can use cancer specific DNA transcription
promotor regions
› Virus can enter all host cells, but can only use
the protein synthesis mechanisms of the cancer
cell
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Prokaryotes
› No nucleus
› Free ribosomes
› No organelles
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Circular DNA + small
circles called
plasmids
› Plasmids have been
used to introduce
foreign genes into
bacteria
Unique forms of
inheritance
that only
bacteria have.
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Used to make yogurt,
cheese, wine, beer &
vinegar.
E. coli live in your large
intestine and help
breakdown food
Also live elsewhere on
body & help defend
body from other species
that might cause
disease.
Important decomposers
Used to make
medicines
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Pathogenic bacteria
Cholera
Plague
Tuberculosis
Tetanus – actually
waste product
causes symptoms
› Syphilis
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Just harmful
› Acne
› Strep throat
› Plaque on teeth
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Share characteristics of
bacteria
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Size and shape
Prokaryote
Circular DNA
No RNA processing
Share characteristics of
Eukarya
› Histones associate with
DNA
› DNA replication and
repair process
› Other metabolic
pathways
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Some
characteristics
uniquely Archaea
› Cell wall has
unique molecular
structure
› Cell membrane has
unique
components
› Some metabolic
pathways unique
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Up to 122 º C (252 º F)
around thermal vents
Cold temperatures of
polar oceans
Salt ponds at salinities
of 20-25%
Sulfuric acid at pH 0
Alkaline environments
High pressure of
ocean floor (200 atm)
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Hard to rear in lab
Enzymes used in PCR
for DNA research
Can be used to
breakdown oil and
materials toxic to
other organisms
Feed on minerals and
can be used to
eliminate mineral
build up in power
plant cooling systems.
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Aerobic Respiration
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Anaerobic Respiration
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Some bacteria use oxygen to
generate cell energy.
Cyanobacteria were the first
organisms to add oxygen to the
atmosphere by photosynthesis.
Still important oxygen producers
today
Use alternative energy pathways
and can’t function in the presence
of oxygen.
Tend to be found in sludge at the
bottom of lakes or in other places
that lack oxygen.
A) There would be no more pathogens
on earth.
B) Human populations would thrive in
the absence of disease.
C) There would be little change in
earth’s ecosystems.
D) The recycling of nutrients would be
greatly reduced.
E) The number of organisms on earth
would decrease by 10–20%.
A) DNA
B) ribosomes
C) cytoplasm
D) RNA
E) mitochondria
A) Viruses cannot replicate their own nucleic
acids; bacteria can.
B) Viral genomes can be replicated faster
than bacterial genomes.
C) Viruses can replicate their own nucleic
acids; bacteria can’t.
D) Viruses replicate using transduction;
bacteria replicate using conjugation.
E) Viral genomes are RNA; bacteria genomes
are DNA.
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First Eukaryotes
› Have a nuclear
membrane
 Double layer with pores
 Regulates the molecules
that interact with DNA
 Probably formed as an
in pocketing of the cell
membrane
› Acritarch fossils 1.9
billion years old = first
eukaryotes
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Cell organelles
› Some formed from
invaginations of cell
membrane
› Some by
endosymbiosis
› Performed
specialized
functions
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Larger size
Cell respiration
enables these cells
to produce more
energy
› Can be more active
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Move by cilia or
flagella
Feed on other
organisms
› Phagocytosis
› Endocytosis
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Digested in food
vacuole
Elimination by
exocytosis
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Photoautotrophs
› Feed themselves by
capturing sun
energy to make
sugar molecules
› = Photosynthesis
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Euglena can also
hunt prey when little
light is available
Some are colonial
Some multicellular
forms are included =
seaweed
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Reproduce by
spores
Heterotrophic, but
digest outside of
body
Tend to be
sedentary and move
by adding cells to
colony
› Slime molds can
form a creeping
slug
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Trypanosoma –
sleeping sickness
Transmitted by insect
Vaccine difficult
because proteins of
cell membrane
change with every
cell division
Leads to lethargy,
coma and death
A) Cyanobacteria
B) Chemolithotrophs
C) Chemoorganotrophs
D) Retroviruses
E) Plants
A) global warming.
B) ecological research.
C) forestry.
D) waste clean up.
E) agriculture.
A) prokaryotic.
B) multicellular.
C) eukaryotic.
D) marine.
E) photosynthetic.
A) Plants
B) Fungi
C) Archaea
D) Animals
E) Bacteria
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Cell membrane +
Cell wall with outer
capsule layer
Pili on outer surface
have various
functions such as
attaching to solid
surface or moving
across that surface