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