Bacteria
Lab 16
Bacteria
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Prokaryotes lack organelles.
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Bacteria are the simplest forms of life.
Bacteria contain DNA, but it is not
contained in a nucleus.
Bacteria reproduce by fission –
they simply split in two.
Bacteria
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Most bacteria are saprotrophic –
they send out digestive enzymes
into the environment and then take
up the nutrient molecules.
Some bacteria are parasitic and
cause disease.
Bacteria
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Others are photosynthetic or
chemosynthetic making organic
(food) molecules from inorganic
molecules.
A colony contains cells that are all
descended from one original cell.
Shapes of Bacteria
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Bacteria come in 3
shapes:
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Bacillus (rod)
Coccus (round)
Spirillum (spiral)
Images by Biodisc company.
Bacterial Structure
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Basic structure
includes a loop of
DNA, ribosomes,
a plasma
membrane, a cell
wall, sometimes a
capsule.
Some bacteria
move about using a
flagellum.
Pili are used for
attachment.