Download Domain Bacteria and Archea

Domain Bacteria and Archea
Prokaryotes
• A prokaryote is a single-celled organism that
lacks a nucleus.
• “___________ bacteria are prokaryotes!”
• Remembering classification
– Domain Bacteria
– Domain Archea
– Domain Eukarya
Domain Archea
• Kingdom
Archeabacteria
– Lack peptidoglycan
– DNA in genes is more
similar to eukaryotes
than bacteria
– Harsh environments
• Three Types:
– Methanogens
– Halophiles
– Thermophiles
Halophilic
•
•
•
•
“salt-loving”
Photosyntheic
Autotrophic
Use Pigment
bacteriorhodopsin that
uses all light except for
purple light, making the
cells appear purple.
Thermophilic
• Hot springs and thermal
vents
• Anaerobic=Don’t use
oxygen
• contain genes for heatstable enzymes
• An example is taq
polymerase, the gene for
which was isolated from a
collection of Thermus
aquaticus in a Yellowstone
Park hot spring.
• Taq polymerase is used to
make large numbers of
copies of DNA sequences in
a DNA sample.
• Annual sales of taq
polymerase are roughly half
a billion dollars!
Methanogens
• These archeabacteria
are anaerobes.
• They make methane
(natural gas) as a waste
product.
• swamp sediments,
sewage, and in buried
landfills.
• Bioremediation in
landfills
Domain Bacteria
• Bacteria are of
immense importance
because of their rapid
growth, reproduction,
and mutation rates, as
well as, their ability to
exist under adverse
conditions.
• The oldest fossils
known, nearly 3.5
billion years old, are
fossils of bacteria-like
organisms.
Autotrophs or heterotrophs
• Those that are classified
as autotrophs are either
photosynthetic,
obtaining energy from
sunlight or
chemosynthetic,
breaking down
inorganic substances for
energy .
Heterotrophic Bacteria
• breaking down complex
organic compounds in
the environment.
• saprobes: bacteria that
feed on decaying
material and organic
wastes,
• Parasites: absorbing
nutrients from living
organisms.
Eubacteria- “true” bacteria
• Live almost everywhere
• Have no organelles
• Peptidoglycan in cell
walls
• Cell wall
• Cell membrane within
the cell wall
Short Video
Structure of Bacteria
See coloring sheet
• The Gram stain, which divides most clinically
significant bacteria into two main groups, is
the first step in bacterial identification.
• Bacteria stained purple are Gram + - their cell
walls have thick petidoglycan and teichoic
acid.
• Bacteria stained pink are Gram – their cell
walls have have thin peptidoglycan and
lipopolysaccharides with no teichoic acid.
3 Types of Bacteria
Bacilli- rod shaped
Cocci- spherical
Spirilla- spiral shaped
Bacterial Growth and Reproduction
• Bacteria can reproduce sexually by conjugation or
asexually by binary fission.
Are bacteria bad? (no)
Cyanobacteria were the first organisms on Earth to do modern
photosynthesis and they made the first oxygen in the Earth's
atmosphere.
• Bacteria are often
maligned as the causes
of human and animal
disease. However,
certain bacteria, the
actinomycetes, produce
antibiotics such as
streptomycin and
nocardicin.
• Still other Bacteria
live on the roots of
certain plants,
converting
nitrogen into a
usable form.
• Nitrogen-fixing
bacteria
• Bacteria put the tang in
yogurt and the sour in
sourdough bread.
• Saprobes help to break
down dead organic
matter.
• Bacteria make up the
base of the food web in
many environments.
Streptococcus thermophilus in yogurt
• Bacteria are prokaryotic and unicellular.
• Bacteria have cell walls.
• Bacteria have circular DNA called plasmids
• Bacteria can be anaerobes or aerobes.
• Bacteria are heterotrophs or autotrophs.
• Bacteria are awesome and all over the place!!!