Taking a Closer Look at Kingdom Eubacteria, Archaea

and VirusesObjectives:

1. Compare and contrast Eubacteria, Archaea and Viruses

2. Explain why viruses are not part of any of the 6 kingdoms

3. Discuss some benefits and negatives of bacteria

Microscopic Organisms• Microscopic bacteria and viruses are the cause of

many diseases.– Respiratory infections– Flu– Plague

• They also play an important role in the ecosystem.– Recycling nutrients (convert nitrogen into a form plants can

use)– Production (Cheese, Yogurt, Vitamin K and B12)– Sewage Treatment– Digestion– Decomposer– Produce antibiotics (to compete with other bacteria)

Prokaryotes• Domain Eubacteria and Archaea are single-

celled and lack membrane bound organelles.

• Extremely small• Dominate forms of life because they live in

every habitat– Inside and on other organisms (100 trillion+ on

your body!)– In water and soil (even deep within the Earth)– In boiling hot springs– In acid and even on and in ice!!! (Totally

extreme)

Yellowstone National Park

Cell Shapes

• Both Archaea and Eubacteria can be classified based on their shape..– Bacillus (rod shaped)

E.coli– Coccus (round)

Streptococcus

– Spirillum (spiral)

Spirillum minus

Eubacteria

• Consist of a cell wall ( composed of __________________which makes the cell strong) and a plasma membrane surrounding the cytoplasm.

• Chromosome is ___________________________.

• Also may contain _______________(small loop of extra DNA with a few genes)

• Contains ribosomes which make ___________________

• Have flagellum for ______________________• ____________help cell attach to surfaces

Metabolism

• Autotrophic bacteria: Make their own food– Cyanobacteria or blue-green algae, blue-green

bacteria

– Use energy from the sun (photosynthesis)

• Heterotrophic bacteria: Get nutrients from other organisms– Heterotrophic bacteria include parasitic types

– E.Coli - The products of their metabolism may be toxic to animals

Reproduction - Asexually• Reproduce asexually by binary

fission.• Similar to mitosis

– DNA replicates– Cell elongates– Cell splits apart

• Also may be subject to mutations.– Bacteria reproduce rapidly so

mutations occur more frequently

• Bacteria can gain new DNA through infection by a virus or conjugation.

• Conjugation: Form of sexual-like reproduction (two cells join and exchange genetic info.)

Archaea

• Similar to bacteria in some ways…– Have a cell wall, but lack peptidoglycan– Different genetic information– Can occupy much more extreme

environments (acidic, boiling)

SubgroupsMethanogens: Live in low oxygen environments

- Swamps, Sewage lagoons, Digestive tracts- Convert methane gas into energy

Halophiles: Salt lovers that live in environments that are very salty

- Dead Sea, Foods preserved by salt- Convert food molecules into energy

Extreme Thermophiles: Live in very hot environments (70 - 95ºC is optimal for growth)

Psychrophiles: Live in Antarctic and Artic environments

(-10 to – 20 ºC is optimal for growth)

Viruses• Non–living infectious particles that

pass from cell to cell and organism to organism.

• They infect a cell and take over control forcing or tricking the cell into making copies of the virus.

Your Turn

• Complete the hand out on ‘Comparing and Contrasting the structure and function of Prokaryotes, Eukaryotes and Viruses.

Plenary

1. Compare and contrast Archaea and Eubacteria (how are they similar and different)

2. How do bacteria reproduce?

3. How are bacteria classified?

4. How are bacteria harmful/helpful?

5. Why are viruses considered to be non-living?

6. Compare and contrast virus and bacteria reproduction.

Additional Questions

• H/W• Page 344 #1, 2, 4, 6, 7• Make a table to summarize the benefits of

bacteria and the harmful effects of bacteria