http://www.youtube.com/watch?v=tqOVYpkZ0qsBacteria song

3 DOMAINS – Tree of Life

More on Classification

Why the change from 5 kingdom to 6 kingdom?

• Prokaryotes:

• Eukaryotes:

• What came first: Prokaryote or eukaryote?

Prokaryotes vs. Eukaryotes

Archaea VS Bacteria

Single celledProkaryotes

Ribosomes, Cell Wall, (Flagella –

optional)

Common Ancestor

Size/Shape

Mesophiles

Cell wall composed of protein

Cell wall composed of peptidoglycan

(sugar-protein complex)

DNA, RNA, protein synthesis machinery

DNA, RNA, protein synthesis machinery

Extremophiles

Reproduction Reproduction

Mesophiles

Do not respond to antibiotics

http://www.youtube.com/watch?v=N-EYTtxsL8gWhere they are found

Single celledProkaryotes

Ribosomes, Cell Wall, (Flagella –

optional)

Common Ancestor

Size/Shape

Mesophiles

Cell wall composed of protein

Cell wall composed of peptidoglycan

(sugar-protein complex)

DNA, RNA, protein synthesis machinery

DNA, RNA, protein synthesis machinery

Extremophiles

Reproduction Reproduction

Mesophiles

Do not respond to antibiotics

BACTERIA

Methods of Classification• Shape• Gram Staining• Habitat• Nutrition

DIFFERENT SHAPES

Coccus (pl. cocci)

Bacillus (pl. bacilli)

Spirochetes (pl. spirilli)

- Gram stain applied to bacteria to determine cell wall composition

Gram Staining

Gram-negative bacteria

Gram Staining Results

Gram-positive bacteria

HabitatMETHANOGENS- Produce methane gas- Found in guts of

some animals

HALOPHILES- Salt loving

THERMOPHILES- Heat lovers

MESOPHILES- Live in moderate temperatures of 15-40ºC

Nutrition

Autotrophs - Heterotrophs –

Defense!!!!

• http://www.youtube.com/watch?v=JnlULOjUhSQ&feature=related

• White blood cell eating bacteria

• Naturally our immune system fights them

• Give Antibiotics

Reproduction in Bacteria

Why study reproduction in

bacteria?

What is the advantage of asexual vs. sexual

reproduction?

http://www.youtube.com/watch?v=gEwzDydciWc

Conjugation

http://www.youtube.com/watch?v=O-EdX4MaMFE

Transformation

Transduction

Endospore Formation

Question: Why is the formation of an endosporebeneficial to the bacteria?

BENEFICIAL USES OF BACTERIA

• Nitrogen fixation

• Recombinant DNA technology

• Genetic studies

Other Applications of Bacteria• Waste Management – bioremediation uses

bacteria to remove toxic material (oil, acid, pesticides, radioactive wastes)

• Sewage Treatment – bacteria decompose organic matter (i.e. septic tanks with human feces)

• Dairy Foods – used to create dairy products (texture, flavour).– Probiotic bacteria in yogurt!