Chapter 27: Prokaryotes 1.Where can you find prokaryotes? -EVERYWHERE!! -Domain Bacteria & Archae 2.What do you know about bacterial structure, function & reproduction? -3 shapes: round (cocci), rod (bacilli) & helical (spirilla & spirochetes)

Figure 27.2 The most common shapes of prokaryotes 1  m 2  m 5  m (a) Spherical (cocci) (b) Rod-shaped (bacilli) (c) Spiral

Chapter 27: Prokaryotes 1.Where can you find prokaryotes? -EVERYWHERE!! -Domain Bacteria & Archae 2.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)

Figure 27.3 Gram staining Peptidoglycan layer Cell wall Plasma membrane Protein Gram- positive bacteria 20  m Outer membrane Peptidoglycan layer Plasma membrane Cell wall Lipopolysaccharide Protein Gram- negative bacteria (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.

Chapter 27: Prokaryotes 1.Where can you find prokaryotes? -EVERYWHERE!! -Domain Bacteria & Archae 2.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

200 nm Capsule 200 nm Fimbriae Figure 27.4 CapsuleFigure 27.5 Fimbriae

Chapter 27: Prokaryotes 1.Where can you find prokaryotes? 2.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

Figure 27.7 Specialized membranes of prokaryotes (a) Aerobic prokaryote(b) Photosynthetic prokaryote 0.2  m1  m Respiratory membrane Thylakoid membranes

Chapter 27: Prokaryotes 1.Where can you find prokaryotes? 2.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)

Figure 27.9 An endospore Endospore 0.3  m

Chapter 27: Prokaryotes 1.Where can you find prokaryotes? 2.What do you know about bacterial structure, function & reproduction? 3.How can prokaryotes obtain energy & carbon?

Table 27.1 Major Nutritional Modes

Chapter 27: Prokaryotes 1.Where can you find prokaryotes? 2.What do you know about bacterial structure, function & reproduction? 3.How can prokaryotes obtain energy & carbon? 4.What are the metabolic relationships to oxygen? -Obligate aerobes – require O 2 -Facultative anaerobes – prefer O 2 but can do fermentation -Obligate anaerobes – poisoned by O 2 – can do fermentation & some can use anaerobic respiration 5.What is the origin of photosynthesis? -Cyanobacteria (formerly known as blue-green algae) -H 2 S metabolizing bacteria mutated to use……. -H2O-H2O -Released O 2 reacted with dissolved iron -Formed iron oxide precipitate

Figure Banded iron formations: evidence of oxygenic photosynthesis

Chapter 27: Prokaryotes 1.Where can you find prokaryotes? 2.What do you know about bacterial structure, function & reproduction? 3.How can prokaryotes obtain energy & carbon? 4.What are the metabolic relationships to oxygen? 5.What is the origin of photosynthesis? -Cyanobacteria (formerly knowns as blue-green algae) -H 2 S metabolizing bacteria mutated to use……. -H 2 O -Released O 2 reacted with dissolved iron -Formed iron oxide precipitate 6. Figure shows the phylogeny of prokaryotes

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

Chapter 27: Prokaryotes 1.Where can you find prokaryotes? 2.What do you know about bacterial structure, function & reproduction? 3.How can prokaryotes obtain energy & carbon? 4.What are the metabolic relationships to oxygen? 5.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 6.Figure shows the phylogeny of prokaryotes 7.What are the differences between each of the domains?

Table 27.2 A Comparison of the Three Domains of Life

Chapter 27: Prokaryotes 1.Where can you find prokaryotes? 2.What do you know about bacterial structure, function & reproduction? 3.How can prokaryotes obtain energy & carbon? 4.What are the metabolic relationships to oxygen? 5.What is the origin of photosynthesis? 6.Figure shows the phylogeny of prokaryotes 7.What are the differences between each of the domains? 8.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 (+/-) 9.How can you determine if a pathogen causes a disease? -Koch’s postulates 1.Find the same pathogen in all diseased individuals 2.Isolate the pathogen & grow it in pure culture 3.Induce the disease in naïve animals 4.Re-isolate the pathogen

Chapter 27: Prokaryotes 1.Where can you find prokaryotes? 2.What do you know about bacterial structure, function & reproduction? 3.How can prokaryotes obtain energy & carbon? 4.What are the metabolic relationships to oxygen? 5.What is the origin of photosynthesis? 6.Figure shows the phylogeny of prokaryotes 7.What are the differences between each of the domains? 8.What are some ecological impacts of bacteria? 9.How can you determine if a pathogen causes a disease? -Koch’s postulates 1.Find the same pathogen in all diseased individuals 2.Isolate the pathogen & grow it in pure culture 3.Induce the disease in naïve animals 4.Re-isolate the pathogen 10. How can bacteria harm us? -Disease – Lyme disease -Exotoxin – secreted chemicals – botulism, cholera -Endotoxin – released upon bacterial death - Salmonella