Oxidized into nitrate or nitrite and used to

oxidized into nitrate or nitrite and used to fertilize crops to
feed the growing population.
 Bacteria:
o The first life forms that originated 3.8 billion years ago
o Archaea dominated the planet until about 1.5 billion years ago when eukaryotes
were created.
o In the human body there are probably about twice as many bacterial cells as
human cells.
o Bacteria are called prokaryotes and lack nucleus, cytoskeleton or sex.
o There are very few bacterial species.
o Importance of Bacteria:
 Photosynthesis
 Nitrogen – fixation

 Biogeochemical cycles
 Decomposition
 Production of soils
 Basis of food webs in the ocean and on land
 Food such as cheese, beer, wine, soy sauce, pickles, etc.
o Less than 0.5% of bacteria cause diseases, however they are very deadly such as
Tuberculosis.
o Cyanobacterial products:
 Oxygen
 Ozone
 Nitrogen/Ammonium
 Gold
 Copper
 Iron
 Limestone
 Plants and algae (chloroplast)
o Prokaryotes VS Eukaryotes:
Prokaryotes Eukaryotes
 Lack nuclei
 Have cell walls
 DNA floats around freely
 Not bounded
 No sex
 Very small
 Reproduce at a very fast
rate
 Have nuclei
 Animal cells don’t have cell
walls, but plant cells do
 Mitochondria
 DNA is bound together by a
plasma
 Membrane-bound organelles
 MUCH larger than
prokaryotes