1. 2/28/12
What is a halophile?
Key Term: archaea

2. 3/1/12 What compound makes up the cell wall of a bacterium?
Key terms: same as yesterday

3. Prokaryotes Domain Bacteria Domain Archaebacteria Domain Bacteria
Archaea
Eukarya
Common ancestor

4. Bacteria Structures

5. Bacteria Structures/Functions
Flagella
Tail-like structure for movement
Pili
Projection of cell wall for sticking to surfaces
Cell wall
Maintains shape of cell; protects the cell
Cell membrane
Regulates what leaves and enters the cell
DNA
Stores hereditary information
Ribosomes
Builds proetins

6. Prokaryote Structure Unicellular Size Internal structure
prokaryote cell
Unicellular
bacilli, cocci, spirilli
Size
1/10 size of eukaryote cell
1 micron (1um)
Internal structure
no internal compartments
no membrane-bound organelles
only ribosomes
circular, naked DNA
not wrapped around proteins

7. Genetic variation in bacteria
Mutations
bacteria can reproduce every 20 minutes
binary fission
error rate in copying DNA
1 in every 200 bacteria has a mutation
Genetic recombination
bacteria swap genes
plasmids
small supplemental circles of DNA

8. Genetic Recombination
Type
Source of New genes
Entry method
Transformation
DNA in surroundings
Endocytosis
Transduction
Virus w/bacterial DNA
Viral mediated entry
Conjugation
Other bacteria
Pili bridge

9. Archaebacteria Extremophiles:
Thermoacidophiles – love heat (up to 110’C) and acidic environments; require sulfur; anaerobic ex: Sulfolobus, Pyrodictium
Halophiles –love environments with high salt concentrations like the Great Salt Lake and the Dead Sea; nearly all aerobic; all Gram-negative ex: Halococcus
Methanogens – anaerobic methane producers; use carbon dioxide; live in soil, swamps, digestive tracts ex: Methanococcus

10. Bacterial diversity
rods and spheres and spirals… Oh My!

11. Prokaryote Cell Wall Structure
peptide side
chains
cell wall
peptidoglycan
plasma membrane
protein
Gram-positive bacteria
That’s important for your doctor to know!
peptidoglycan = polysaccharides + amino acid chains
lipopolysaccharides = lipids + polysaccharides
Gram-negative bacteria
peptidoglycan
plasma
membrane
outer
outer membrane of lipopolysaccharides
cell wall

12. Bacteria live EVERYWHERE!
Bacteria live in all ecosystems
on plants & animals
in plants & animals
in the soil
in depths of the oceans
in extreme cold
in extreme hot
in extreme salt
on the living
on the dead

13. Prokaryotic metabolism
How do bacteria acquire their energy & nutrients?
photoautotrophs
photosynthetic bacteria
chemoautotrophs
oxidize inorganic compounds
nitrogen, sulfur, hydrogen…
heterotrophs
live on plant & animal matter
decomposers & pathogens

14. Variations in Cell Interior
cyanobacterium (photosythetic) bacterium
aerobic bacterium
internal membranes for photosynthesis like a chloroplast (thylakoids)
internal membranes for respiration like a mitochondrion (cristae)

15. Bacteria as pathogens Disease-causing microbes plant diseases
wilts, fruit rot, blights
animal diseases
tooth decay, ulcers
anthrax, botulism
plague, leprosy, “flesh-eating” disease
STDs: gonorrhea, chlamydia
typhoid, cholera
TB, pneumonia
lyme disease

16. Do you recognize…?

17. Bacteria as beneficial (& necessary)
Life on Earth is dependent on bacteria
decomposers
recycling of nutrients from dead to living
nitrogen fixation
only organisms that can fix N from atmosphere
needed for synthesis of proteins & nucleic acids
plant root nodules
help in digestion (E. coli)
digest cellulose for herbivores
cellulase enzyme
produce vitamins K & B12 for humans
produce foods & medicines
from yogurt to insulin

18. Pathogenic Bacteria Name of bacteria
Can you predict the shape from name?
Gram-Stain
(+ = purple,
= pink)
Shape
Notes