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Bacteria Guided Reading
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What are prokaryotes?
Single celled organisms that DO NOT
have membrane bound organelles.
3 Common Bacterial Shapes
Sphere Shaped  Coccus
Rod Shaped  Bacillus
Spiral Shaped  Spirillum
3 Common Bacterial Shapes
2 Domains all Prokaryotes Belong to:
Domain Archaea
Domain Bacteria
Domain Archaea
Kingdom Archaebacteria
– Mostly found in EXTREME Environments
– Salt Lakes / Hot Springs / etc
Domain Bacteria
Can be found virtually EVERYWHERE!!!
100,000 found on 1 sq in of your skin!
Bacterial Structure
Genetic Material  DNA
Bacterial DNA is a single chromosome
clusered in a mass called a nucleoid.
Bacterial Structure
Plasmids?
– Small, circular extra loops of DNA
Other non-membrane bound structures?
– Ribosomes, enzymes, nutrients
Bacterial Structure
Outside Cell Membrane?
– Rigid cell wall – 1 or 2 layers thick
Cell wall made of?
– Peptidoglycan
Outside cell wall of some?
– Additional membrane
Up Close: E. coli
Identifying Bacteria
Techniques Used to ID Bacteria
– Gram Staining
Gram Positive
Thick layer of peptidoglycan / no outer
membrane
EASIER to Kill!!!
Stain PURPLE
Gram Negative
Thin layer peptidoglycan / outer
membrane present
HARDER to Kill!!!
Stains Pink
Gram Negative Membrane
Makes them more resistant to host
defenses & medicines!
Obtaining Energy
Photoautrotrophs
– Use SUNLIGHT for energy
– Purple & Green Sulfur Bacteria
– CYANOBACTERIA
Chemoautotrophs
– Get energy from Inorganic Sources (CHEMICALS) in
their environment
Heterotrophs
– Feed on DEAD organisms
– Paratites / Pathogens (Feed on LIVING stuff)
Asexual Reproduction
Binary Fission
– A single cell divides into two identical cells
– (MITOSIS)
Sexual Reproduction
Conjugation
– Occurs when two bacteria join to exchange
DNA
– Connect through Pili
Other Methods
Transformation
– Bacteria pick up
DNA fragments from
environment
Transduction
– Genetic material
(like a plasmid) is
transferred by a
virus
Endospores
Thick walled structures that surround DNA
& cytoplasm, protecting bacteria from
harsh conditions
Vital Role of Bacteria
Produce Oxygen
Convert Nitrogen to useable form for
Plants (matter cycles)
DECOMPOSERS!!!
Food we eat!
Helpful in Industry / Research
Produce Chemicals (Acetone)
Clean up oil spills / sewage
Produce human proteins
Causing Disease
Producing Toxin
– Clostridium botulinum
– Botulism toxin causes food poisoning
– Used in Botox
Staphylococcus
Flesh Eating Bacteria
Causing Disease
Destroying Body Tissue
Destroying Body Tissue
ANTHRAX
CHLAMYDIA
GONORRHEA
Antibiotics
Chemicals that
inhibit the growth of
or kill
microorganisms.
Conjugation &
Natural Selection
spreads antibiotic
resistance (MRSA)