Bacteria Our invisible friends

Bacteria are prokaryotes Pro – before Karyon – nucleus The simplest forms of life are prokaryotes. Earth’s first cells were prokaryotes.

Lots of Them! Prokaryotes are Earth’s most abundant life forms. They can survive in many environments. They can get energy from many different sources.

Prokaryote Review Mostly single-celled No nucleus or organelles Circular chromosomes Cell walls Reproduce mostly asexually Anaerobic or aerobic Heterotrophic or autotrophic

Archaebacteria Methane producers – anaerobic Halophiles Thermophiles Halo = salt Philia = love Thermophiles Thermo = heat

Eubacteria Parasitic heterotrophs (Streptococcus) Saprophages Sapro = death Phage = eat Cyanobacteria (blue-green algae) Photosynthetic Chemosynthetic autotrophs (Rhizobium)

Bacteria are Named by Shape Cocci (ball-shaped) Streptococcus mutans Bacillus (rod-shaped) Clostridium botulinum Spirilli (spiral-shaped) Treponema palladium

Germ Theory of Disease Joseph Lister – Aseptic Techniques Robert Koch – Germ Theory A specific microorganism causes a specific disease