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Prokaryotes
Archaebacteria and Eubacteria
They are Everywhere
 Very cold, hot, salty, acidic environments
 They exist in our digestive systems, and
in our mouths
 They also help to recycle carbon and
other important nutrients in the soil
2 branches of Monera
 Bacteria and Archaea
 Archaea – extremophiles – they live in
very extreme conditions
 Thermophiles – live in very hot
conditions
 Halophiles – live in very salty conditions
 Methanogens – archaea bacteria that
live in anaerobic conditions and produce
methane gas
Pili on bacteria
Shapes of Bacteria
 Bacilli – rod shaped bacteria
 Coccus – round bacteria (strep/staph)
 Spirochetes – spiral-shaped bacteria (ex.
Syphilis)
 Clostridium botulinum – causes botulism
– produces endospores that can remain
dormant for years
Shapes
Endospores - Anthrax
Bacterial Reproduction
 Bacteria reproduce by binary fission
 Binary fission - when the bacteria
continuously copy their DNA and divide
rapidly.
 Conjugation – the exchange of genetic
material between two bacterial cells
Conjugation
Bacterial Nutrition
 Photoautotrophs – bacteria that
photosynthesize – ex. Cyanobacteria
 Chemoautotrophs – make food from
CO2 and other chemicals
 Chemoheterotrophs – obtain food from
an organic source
Cyanobacteria
Bacterial Pneumonia
Lyme Disease
Lyme Disease
Bacteria that cause disease
 Bacteria and other microorganisms that cause
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disease are called pathogens.
Some bacteria produce exotoxins. Exotoxins
are poisons that are very harmful.
Ex. Staphylococcus aureus produces a flesh
eating exotoxin.
Endotoxins are found in the bacterial cell
membrane
Ex. Salmonella has an endotoxin in its cell
membrane that causes food poisoning
Bacteria and chemical
recycling
 Bacteria recycle nitrogen and carbon in
the soil.
 Bacteria decompose dead and decaying
matter and return vital nutrients to the
soil.
Bioremediation
 Bioremediation – the use of bacteria
decomposers to treat our sewage
 Bacteria are also used to clean oil spills
Gram positive and negative
 Gram staining is a way to determine the
type of bacterial infection present.
 The cell wall determines whether it is a
gram positive or negative bacteria.
Gram Staining
Other facts about bacteria
 Live with other things in symbiotic
relationships
 Ex. Cows do not digest cellulose, but
feed on grass. They have bacteria in
their guts to break down the cellulose.
This is a mutualistic relationship
 Mutualism - when both organisms
benefit from the relationship.
 Bacteria can also use flagella to move