Download Microbiology : Bacteria, Archaebacteria, Eubacteria, reproduction

Microbiology : Bacteria, Archaebacteria, Eubacteria, reproduction and Growth
Reading Assignment: 2.4 Bacteria, from Nelson Text pages108­112
1. Bacteria can be classified into 2 kingdoms, Archaebacteria and Eubacteria. All bacteria possess the following similarities:
all cells are unicellular
cells are prokaryotic(bacteria usually lack membrane bound internal structures
cells have a single DNA loop
cells reproduce asexually by binary fission
cells thrive in moist environments
There are 2 types of cells
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http://www.youtube.com/watch?v=nP9lZG94DO0
There are 2 types of cells eukaryotic and prokaryotic
plant and animal cells are eukaryotic, meaning true nucleus
bacterial cells are prokaryotic, meaning before nucleus
Prokaryotic bacterial cell
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Eukaryotic Animal cell
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Archaebacteria­ means early or primitive
­these organisms come from the oldest group of living organisms on earth
­ 3 major groups of archaebacteria
­thermophiles­ live in hot areas
methanogens­ grow on carbon dioxide and hygrogen to produce methane
halophiles­live in extremely saline environments
this group is used by scientists to clean up environmental spills
Eubacteria­ E.Coli best example of eubacteria
E. Coli is both helpful and harmful to humans, billions of E. Coli live in the human intestine, helping with food digestion and the synthesis of Vitmain K and B
Human and animal feces contain billions of E. Coli ( coliform bacteria) in water can be adanger to human health.
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Eubacteria­ best example is E. Coli
Eubacteria are prokayotic, the most abundant prokaryotic on earth, include the photosynthesizing blue green algae
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Bacteria can be groupedand named by there shape, there are 3 common shapes
­spherical or round bacteria are called ­cocci
rod shaped bacteria are called­bacilli
spiral or coil shaped bacteria are called­spirilla
so it is very easy to determine the shape of a bacterium by looking at its name, staphylococcus bcterium is round because the suffix coccus indicates the round shape of the bacteria.
Many Bacteria reproduce by Binary Fission, this is asexual because there is no exchange of DNA between cells
Reproduction can also happen by conjugation­ this is when a tube forms between 2 bacterium adn small pieces of DNA are passed through the tube and the result is a genetically different bacterium 6
http://www.youtube.com/watch?v=O­EdX4MaMFE
http://www.youtube.com/watch?v=3cD3U2pgb5w
http://www.youtube.com/watch?v=
3cD3U2pgb5w&feature=player_detailpage
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