1 Bacteria

2 Earliest Prokaryotes Most numerousMost numerous organisms on Earth bacteriaInclude all bacteria Earliest fossils dateEarliest fossils date 2.5 billion years old

3 Classification of Life

4 Three Domains of Life Archaea – prokaryotes living in extreme habitatsArchaea – prokaryotes living in extreme habitats Bacteria - Cyanobacteria and eubacteria Bacteria - Cyanobacteria and eubacteria Eukarya – Protozoans, fungi, plants, & animals Eukarya – Protozoans, fungi, plants, & animals

5 Archaebacteria Archaebacteria can live in extremely harsh environmentsArchaebacteria can live in extremely harsh environments They do not require oxygen and can live in extremely salty environments as well as extremely hot environmentsThey do not require oxygen and can live in extremely salty environments as well as extremely hot environments Called the Ancient bacteriaCalled the Ancient bacteria

6 Archaebacteria Lack peptidoglycan in cell wallsLack peptidoglycan in cell walls Have different lipids in their cell membraneHave different lipids in their cell membrane Different types of ribosomesDifferent types of ribosomes Very different gene sequencesVery different gene sequences

7 Archaebacteria Subdivided into 3 groups:Subdivided into 3 groups: Methanogens- anaerobic, methagen producing Methanogens- anaerobic, methagen producing Thermoacidophiles- “heat and acid loving” Thermoacidophiles- “heat and acid loving” Extreme Halophiles- “salt-loving ” Extreme Halophiles- “salt-loving ”

8 Archaebacteria

9 Kingdoms of Bacteria Eubacteria: Called the true bacteria Called the true bacteria Most bacteria are in this group Most bacteria are in this group Include photosynthetic Cyanobacteria Include photosynthetic Cyanobacteria

10 Characteristics 3 basic shapes Bacillus: rod-shapedBacillus: rod-shaped Coccus: sphere-shapedCoccus: sphere-shaped Spirrilla: spiral-shapedSpirrilla: spiral-shaped

11 Grouping of Bacteria Diplo- Groups of twoDiplo- Groups of two Strepto- chainsStrepto- chains Staphylo- Grapelike clustersStaphylo- Grapelike clusters

12 Diplococcus

13 Streptobacilli

14 Staphylococcus Bacterial

15 Staphylococcus

16 Spirillum

17 Characteristics of Bacteria

18 Bacterial Structure Microscopic prokaryotesMicroscopic prokaryotes No nucleus or membrane- bound organellesNo nucleus or membrane- bound organelles Contain ribosomesContain ribosomes Single, circular chromosome in nucleoid regionSingle, circular chromosome in nucleoid region

19 Bacterial Structure Have small rings of DNA called PlasmidsHave small rings of DNA called Plasmids UnicellularUnicellular Small in size (0.5 to 2μm)Small in size (0.5 to 2μm) PLASMIDS

20 Flagella Bacteria that are motile have appendages called flagellaBacteria that are motile have appendages called flagella Attached by Basal BodyAttached by Basal Body A bacteria can have one or many flagellaA bacteria can have one or many flagella

21 Pili Short protein appendagesShort protein appendages Smaller than flagellaSmaller than flagella Adhere bacteria to surfacesAdhere bacteria to surfaces Used in conjugation for Exchange of genetic informationUsed in conjugation for Exchange of genetic information Aid Flotation by increasing buoyancyAid Flotation by increasing buoyancy

22 Bacterial Cell

23 Protection Cell Wall made of PeptidoglycanCell Wall made of Peptidoglycan May have a sticky coating called the Capsule for attachment to host or other bacteriaMay have a sticky coating called the Capsule for attachment to host or other bacteria

24 Useful Bacteria Some bacteria can degrade oilSome bacteria can degrade oil Used to clean up oil spillsUsed to clean up oil spills

25 Benefits of Bacteria Nitrogen Fixation Photosynthesis Decomposers Food production- cheese & yogurt Sewage Treatment- sludge to methane gas

26 Nutrition, and Reproduction

27 Modes of Nutrition Saprobes – feed on dead organic matterSaprobes – feed on dead organic matter Parasites – feed on a host cellParasites – feed on a host cell Photoautotroph – use sunlight to make foodPhotoautotroph – use sunlight to make food Chemoautotroph – oxidize inorganic matter such as iron or sulfur to make foodChemoautotroph – oxidize inorganic matter such as iron or sulfur to make food

28 Reproduction Bacteria reproduce asexually by binary fissionBacteria reproduce asexually by binary fission Single chromosome replicates & then cell dividesSingle chromosome replicates & then cell divides RapidRapid All new cells identical (clones)All new cells identical (clones)

29 Cellular organism copies it’s genetic information then splits into two identical daughter cells

30 Binary Fission E. coli

31 Reproduction Bacteria reproduce sexually by ConjugationBacteria reproduce sexually by Conjugation Form a tube between 2 bacteria to exchange genetic materialForm a tube between 2 bacteria to exchange genetic material Held together by piliHeld together by pili New cells NOT identicalNew cells NOT identical

32 Conjugation

33 Pathological bacteria (disease- causing) Bubonic plague- wiped out part of Europe during the middle ages, fever, buboes (bubo-swollen gland) formed from bleeding lymph nodes. Cholera and typhoid fever- severe diarrhea, vomiting, often fatal, from contaminated water. Dental caries (cavities)- dental caries, holes form in teeth.

34 Disease causing bacteria Diptheria- sore throat, fever, chills, thick gray coating on back of tongue. Dysentery- severe diarrhea, often bloody, can be fatal. Gangrene- affected area begins to necrofy (die) and rot. Gonorrhea- STD, inflammation of urinary and reproductive tracts, often leads to sterility in women. Lyme disease- carried by deer ticks, rash, pain, and swelling in joints.

35 Disease causing bacteria Salmonella- causes severe food poisoning. Syphilis- STD, 1 st stage includes canker sores, 2 nd phase includes rash, 3 rd stage includes insanity, fatal. Tetanus- “lock jaw,” found in soil and rust. Tuberculosis- known as TB, white death, consumption, infects lungs, coughing up blood, often fatal.