1. Bacteria & Protists
Chapters 27 & 28

2. Quiz
1. When using the molecular clock, it is assumed that mutation rates remain constant over time. How do systemists use the molecular clock to infer phylogeny?
2. What is phylogeny?
3. What is the difference between a monophyletic and paraphyletic group?
4. What is adaptive radiation?

3. Species: Panthera pardus Genus: Panthera Family: Felidae Order:
Figure 26.3
Species:
Panthera pardus
Genus:
Panthera
Family:
Felidae
Order:
Carnivora
Class:
Mammalia
Figure 26.3 Linnaean classification.
Phylum:
Chordata
Kingdom:
Animalia
Domain:
Bacteria
Domain:
Archaea
Domain:
Eukarya

4. Objective
SWBAT explain that organisms share many conserved core processes and features by providing specific examples of conserved core processes shared by all domains or within one domain of life.

5. Classification Old 5 Kingdom system New 3 Domain system Monera
Eukaryote
Prokaryote
Old 5 Kingdom system
Monera
Protists
Plants
Fungi
Animals
New 3 Domain system
Bacteria
Archaebacteria
Eukaryotes
Archaebacteria & Bacteria

6. Kingdom Protist
Kingdom Fungi
Kingdom Plant
Kingdom Animal
Kingdom Archaebacteria
Kingdom Bacteria

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

8. 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

9. Bacterial diversity rods and spheres and spirals… Oh My! Rods Spheres

10. Prokaryote Structure Unicellular Size Internal structure
eukaryote 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
prokaryote cell

11. 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)

12. 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

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. 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

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. 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

17. Any Questions??
Thanks to Kim Foglia