domain bacteria and domain archaea bacteria: archaea basic characteristic of both: unicellular...
TRANSCRIPT
Domain Bacteria and Domain Archaea
Bacteria: Archaea
BASIC CHARACTERISTIC of Both:• Unicellular• Heterotrophic or Autotrophic• Prokaryotic
Eubacteria “True Bacteria”
• Archaea “Ancient”- extremophiles
- Thermophiles, - Methanogens
(salt)
(anaerobic waste removal) (Hydrothermal vents)
- Halophiles
How do Bacteria and Archaea
differ? Domain Bacteria
Structural:
Peptidoglycan in cell wall
Molecular: Simple RNA
polymerases
• Domain Archaea• Structural:
• No peptidoglycan in cell wall.
• Molecular:• Complex RNA
polymerase
Gram staining is used to identify bacteria.
Gram-negative bacteria have a thin layer of peptidoglycan and stain red/pink.
Gram-positive bacteria have a thicker peptidoglycan layer and stain purple.
– Stains the peptidoglycan layer. – Gram-positive = Stain color - purple, Thick
peptidoglycan cell wall– Gram-negative = Stain color - Pink, Thin
peptidoglycan cell wall + outer membrane.
E. coli B.subtilis
Why are some bacteria resistant to certain
antibiotics?
GRAM NEGATIVE GRAM POSITIVE
How bacterial resistance occurs!
Basic Bacterial Structure
flagellum
pili
cell wall
Nucleic Acid
cellmembrane
Ribosome
Plasmid
Bacteria are Classified by Shape and Growth Pattern
– Spirilla = spiral shaped
– Bacillus = rod shaped
– Coccus = spherical shaped
- Diplo = pair- Strepto = chain- Staphylo = cluster
Test yourself…Classify these bacteria?
Streptobacillus
Diplococcus
Streptococcus
Spirillus
Genetic Variation in Bacteria
Transformation – Bacterial picks up free DNA and adds it in to its own DNA.
Conjugation –One bacteria transfers DNA to another.
Mutation – Random change in a DNA sequence.
How are Bacteria helpful? Benefit to Ecosystems
Decomposition (CO2)
Chemical Cycling Fix nitrogen in the soil (air to soil) Cyanobacteria (photosynthesis)
Bioremediation – The use of organisms to remove or neutralize pollutants from a contaminated site
Provide Nutrients: Digestion of food in gut Cheese, butter, yogurt, sauerkraut
How are bacteria harmful? Pathogens: Cause Disease
Scarlet Fever - Streptococcus pyogenes Strep Throat – Streptococcus pyogenes Bacterial Meningitis - Neisseria meningitidis Lyme Disease - Borrelia burgdorferi
Produce toxins Botulism
Clostridium botulinum The chemical used in botox
Food Spoilage
Antibiotic Resistance
What do we use to fight infection?
Antibiotics
Vaccines
Antiseptic
Antibiotics Vs Vaccines Antibiotics only treat
bacterial infections Given after someone
is infected Prevents bacterial
growth
Vaccines treat viral or bacterial diseases Given prior to
infection Is made up of a
small dose of the pathogen
Creates antibodies to fight future infections
Antibiotic Sensitivity
Antibiotic Sensitivity - the susceptibility of bacteria to antibiotic
To test antibiotic sensitivity - Thin wafers containing an antibiotic are
placed on an agar plate that is growing bacteria. The bacteria are can’t grow next to the antibiotic they are sensitive to.
Zone of inhibition - area around antibiotic disc where bacterial growth is inhibited.
Antibiotic Resistance - No clear zone (indicate antibiotic resistance) Antibiotic discs are identified by the letter on
the top. Antibiotic Identifier
Penicillin P
Chloramphenicol C
Doxycycline D
Streptomycin S
Ciprofloxacin CIP
Control CNTL
Zone of inhibition
P
D
C
CIP
S
CNTL
2cm
4 cm
5 cm
4 cm 1 cm
CIP
S
P
CNTL
D
C
1 cm
2 cm
3 cm
4 cm 0 cm