BacteriaBacteria Unicellular Prokaryotic – no

nuclear membrane; one circular chromosome

Ribosomes

Classification of Classification of ProkaryotesProkaryotes

Bacteria

Humans and many animals

Eubacteria Archeabacteria

Harsh Environments

Cell Wall Composition

Cell Wall Composition

DiverseEnvironments

Soil

Fresh and salt water

Salty lakesPeptidoglycan Lackspeptidoglyca

nHot springs

O2-free environmentssuch as GI tracts and

thick mud

Structure of BacteriaStructure of Bacteria

Flagella(some bacteria)

DNA Pili

Ribosome

Peptidoglycan

Cell Membrane

CellWall

Shapes of BacteriaShapes of Bacteria

Bacilli(rod-shaped)

Cocci(spherical)

Spirilla(corkscrew)

Metabolic DiversityMetabolic DiversityEnergy Source Heterotrophs get energy from other

organisms Autotrophs make their own food

Photosynthetic Chemosynthetic

Respiration Obligate aerobes requires O2

Obligate anaerobes w/o O2

Facultative anaerobes survive w/ or w/o O2

Binary FissionBinary Fission

DNA replicates, and the cell divides in half

ConjugationConjugation

Exchange genetic material across a hollow bridge

Increases genetic diversity

Spore FormationSpore Formation

Under harsh conditions, an endospore may form to protect DNA

Spore stays dormant until conditions are favorable