1. Chapter 27: Prokaryotes Where can you find prokaryotes? EVERYWHERE!!
Domain Bacteria & Archae
What do you know about bacterial structure, function & reproduction?
3 shapes: round (cocci), rod (bacilli) & helical (spirilla & spirochetes)

2. Figure 27.2 The most common shapes of prokaryotes
(a) Spherical (cocci)
(b) Rod-shaped (bacilli)
(c) Spiral

3. Chapter 27: Prokaryotes Where can you find prokaryotes? EVERYWHERE!!
Domain Bacteria & Archae
What do you know about bacterial structure, function & reproduction?
3 shapes: round (cocci), rod (bacilli) & helical (spirilla & spirochetes)
1 – 5 µm dia. (eukaryotic cells 10 – 100 µm dia.)
Cell wall outside plasma membrane w/ peptidoglycan (not archae)
Gram (+) – lots of peptidoglycan
Gram (-) – less peptidoglycan (more resistant to antibiotics)

4. Figure 27.3 Gram staining (b) (a)
Peptidoglycan
layer
Cell wall
Plasma membrane
Protein
Gram-
positive
bacteria
20 m
Outer
membrane
Lipopolysaccharide
negative
(b)
(a)
Gram-positive. Gram-positive bacteria have
a cell wall with a large amount of peptidoglycan
that traps the violet dye in the cytoplasm. The
alcohol rinse does not remove the violet dye,
which masks the added red dye.
Gram-negative. Gram-negative bacteria have less
peptidoglycan, and it is located in a layer between the
plasma membrane and an outer membrane. The
violet dye is easily rinsed from the cytoplasm, and the
cell appears pink or red after the red dye is added.

5. Chapter 27: Prokaryotes Where can you find prokaryotes? EVERYWHERE!!
Domain Bacteria & Archae
What do you know about bacterial structure, function & reproduction?
3 shapes: round (cocci), rod (bacilli) & helical (spirilla & spirochetes)
1 – 5 µm dia. (eukaryotic cells 10 – 100 µm dia.)
Cell wall outside plasma membrane w/ peptidoglycan (not archae)
Gram (+) – lots of peptidoglycan
Gram (-) – less peptidoglycan (more resistant to antibiotics)
Many have a capsule outside cell wall for adherence
Pili & fimbriae used for adherence

6. Figure 27.4 Capsule Figure 27.5 Fimbriae
200 nm
Capsule
200 nm
Fimbriae

7. Chapter 27: Prokaryotes Where can you find prokaryotes?
What do you know about bacterial structure, function & reproduction?
3 shapes: round (cocci), rod (bacilli) & helical (spirilla & spirochetes)
1 – 5 µm dia. (eukaryotic cells 10 – 100 µm dia.)
Cell wall outside plasma membrane w/ peptidoglycan (not archae)
Gram (+) – lots of peptidoglycan
Gram (-) – less peptidoglycan (more resistant to antibiotics)
Many have a capsule outside cell wall for adherence
Pili & fimbriae used for adherence
Motility (allows for taxis….+/-, photo & chemo)
Flagella 25 nm wide
Helical filaments in spirochetes
Some secrete slimy chemicals for gliding
Small genome, circular chromosome & plasmids
Some have specialized infoldings of plasma membrane

8. Figure 27.7 Specialized membranes of prokaryotes
(a) Aerobic prokaryote
(b) Photosynthetic prokaryote
0.2 m
1 m
Respiratory
membrane
Thylakoid
membranes

9. Chapter 27: Prokaryotes Where can you find prokaryotes?
What do you know about bacterial structure, function & reproduction?
Cell wall outside plasma membrane w/ peptidoglycan (not archae)
Gram (+) – lots of peptidoglycan
Gram (-) – less peptidoglycan (more resistant to antibiotics)
Many have a capsule outside cell wall for adherence
Pili & fimbriae used for adherence
Motility (allows for taxis….+/-, photo & chemo)
Flagella 25 nm wide
Helical filaments in spirochetes
Some secrete slimy chemicals for gliding
Small genome, circular chromosome & plasmids
Some have specialized infoldings of plasma membrane
Asexual reproduction – binary fission
Genetic recombination by
Transformation
Conjugation
Transduction
Some become endospores (Anthrax)

10. Figure 27.9 An endospore
Endospore
0.3 m

11. Chapter 27: Prokaryotes Where can you find prokaryotes?
What do you know about bacterial structure, function & reproduction?
How can prokaryotes obtain energy & carbon?

12. Table 27.1 Major Nutritional Modes

13. Chapter 27: Prokaryotes Where can you find prokaryotes?
What do you know about bacterial structure, function & reproduction?
How can prokaryotes obtain energy & carbon?
What are the metabolic relationships to oxygen?
Obligate aerobes – require O2
Facultative anaerobes – prefer O2 but can do fermentation
Obligate anaerobes – poisoned by O2 – can do fermentation & some can
use anaerobic respiration
What is the origin of photosynthesis?
Cyanobacteria (formerly known as blue-green algae)
H2S metabolizing bacteria mutated to use…….
H2O
Released O2 reacted with dissolved iron
Formed iron oxide precipitate

14. Figure 26.12 Banded iron formations: evidence of oxygenic photosynthesis

15. Chapter 27: Prokaryotes Where can you find prokaryotes?
What do you know about bacterial structure, function & reproduction?
How can prokaryotes obtain energy & carbon?
What are the metabolic relationships to oxygen?
What is the origin of photosynthesis?
Cyanobacteria (formerly knowns as blue-green algae)
H2S metabolizing bacteria mutated to use…….
H2O
Released O2 reacted with dissolved iron
Formed iron oxide precipitate
6. Figure shows the phylogeny of prokaryotes

16. Figure 27.12 A simplified phylogeny of prokaryotes
Domain Bacteria
Domain
Archaea
Eukarya
Alpha
Beta
Gamma
Epsilon
Delta
Proteobacteria
Chlamydias
Spirochetes
Cyanobacteria
Gram-positive
bacteria
Korarchaeotes
Euryarchaeotes
Crenarchaeotes
Nanoarchaeotes
Eukaryotes
Universal ancestor

17. Chapter 27: Prokaryotes Where can you find prokaryotes?
What do you know about bacterial structure, function & reproduction?
How can prokaryotes obtain energy & carbon?
What are the metabolic relationships to oxygen?
What is the origin of photosynthesis?
Cyanobacteria aka blue-green algae
H2S metabolizing bacteria mutated to use…….
H2O
Released O2 reacted with dissolved iron
Formed iron oxide precipitate
Figure shows the phylogeny of prokaryotes
What are the differences between each of the domains?

18. Table 27.2 A Comparison of the Three Domains of Life

19. Chapter 27: Prokaryotes Where can you find prokaryotes?
What do you know about bacterial structure, function & reproduction?
How can prokaryotes obtain energy & carbon?
What are the metabolic relationships to oxygen?
What is the origin of photosynthesis?
Figure shows the phylogeny of prokaryotes
What are the differences between each of the domains?
What are some ecological impacts of bacteria?
Chemical cycling
Symbiotic relationships
Mutualism – both organisms benefit (+/+)
Commensalism – only 1 benefits (+/___)
Parasitic – 1 benefits & the other harmed (+/-)
How can you determine if a pathogen causes a disease?
Koch’s postulates
Find the same pathogen in all diseased individuals
Isolate the pathogen & grow it in pure culture
Induce the disease in naïve animals
Re-isolate the pathogen

20. Chapter 27: Prokaryotes Where can you find prokaryotes?
What do you know about bacterial structure, function & reproduction?
How can prokaryotes obtain energy & carbon?
What are the metabolic relationships to oxygen?
What is the origin of photosynthesis?
Figure shows the phylogeny of prokaryotes
What are the differences between each of the domains?
What are some ecological impacts of bacteria?
How can you determine if a pathogen causes a disease?
Koch’s postulates
Find the same pathogen in all diseased individuals
Isolate the pathogen & grow it in pure culture
Induce the disease in naïve animals
Re-isolate the pathogen
How can bacteria harm us?
Disease – Lyme disease
Exotoxin – secreted chemicals – botulism, cholera
Endotoxin – released upon bacterial death - Salmonella