Prokaryotes
Characteristics of prokaryotes?





Singular, circular loop of DNA
Small
No membrane-bound organelles
Cell wall
Binary fission for reproduction (asexual)
Gram Staining
Bacteria have peptidoglycan in cell walls
 Some have more, some have less with lipid covering
 Gram staining
 Gram positive & gram negative
Movement
 Not all bacteria move but if they do they usually use
 Flagella
 Slime
Bacteria can cause disease
 Strep throat
 Tuberculosis
 Tetanus
 Lyme Disease
 Dental cavities
 Diphtheria – from contaminated water
 The Bubonic Plague – transmitted from fleas
 STDs such as chlamydia, gonorrhea, syphilis
 Food Poisoning (E. coli)
Oxygen Metabolism
 Obligate aerobes
 Obligate anaerobes
 Facultative anaerobes
Nitrogen Metabolism
 Why is it important?
 Some bacteria can convert atmospheric nitrogen (N2)
to ammonia (NH3)
 “Nitrogen Fixation”
 Heterocysts – cells that carry out nitrogen fixation
Reproduction
 Binary fission
Genetic Diversity in Prokaryotes
 Fast reproduction rate
 Mutations
 Genetic Recombination
 Transformation- uptake of foreign DNA from surroundings
 Transduction- viruses introduce new DNA
 Conjugation- DNA transferred between two prokaryotic cells
Importance of Bacteria
 They change “FIX” NITROGEN from the air so organisms can
use it
 Recycle nutrients (oxygen) and decompose
 Food: Swiss cheese, pickles, yogurt, vinegar, sauerkraut
 Symbiotic relationships
 Research, medicine, bioremediation
Pathogenic Bacteria
 Disease caused by poisons
 Endotoxins
 Exotoxins