1 Bacteria Structure and Function

2 Prokaryote & Eukaryote Evolution

3 Cellular Evolution Current evidence indicates that eukaryotes evolved from prokaryotes between 1 and 1.5 billion years agoCurrent evidence indicates that eukaryotes evolved from prokaryotes between 1 and 1.5 billion years ago Two theories:Two theories: 1.Infolding theory 2.Endosymbiotic theory

4 Infolding Theory The infolding of the prokaryotic plasma membrane gave rise to eukaryotic organelles.The infolding of the prokaryotic plasma membrane gave rise to eukaryotic organelles. infolding organelle

5 Endosymbiotic Theory Endosymbiosis refers to one species living within another(the host)Endosymbiosis refers to one species living within another(the host) Movement of smaller photosynthetic & heterotrophic prokaryotes into larger prokaryotic host cellsMovement of smaller photosynthetic & heterotrophic prokaryotes into larger prokaryotic host cells Formed cell organellesFormed cell organelles chloroplast mitochondria

6 Kingdoms of Bacteria Archaebacteria: Found in harsh environments Found in harsh environments Undersea volcanic vents, acidic hot springs, salty water Undersea volcanic vents, acidic hot springs, salty water

7 Archaebacteria

8 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

9 Eubacteria

10 Characteristics of Bacteria

11 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

12 Bacterial Cell

13 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

14 Sticky Bacterial Capsule

15 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

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17 Bacterial Structure Most grow best at pH of 6.5 to 7.0Most grow best at pH of 6.5 to 7.0 Many act as decomposers recycling nutrientsMany act as decomposers recycling nutrients Some cause diseaseSome cause disease

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

19 Useful Bacteria Other uses for bacteria include making yogurt, cheese, and buttermilk.Other uses for bacteria include making yogurt, cheese, and buttermilk.

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

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22 MonotrichousLophotrichous AmphitrichousPeritrichous

23 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

24 Pili in Conjugation

25 Bacterial Shapes

26 Shapes Are Used to Classify Bacillus: Rod shapedBacillus: Rod shaped Coccus: Spherical (round)Coccus: Spherical (round) Spirillum: Spiral shapeSpirillum: Spiral shape

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

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31 Diplococcus

32 Streptococcus Causes Strep Throat

33 Staphylococcus

34 Bacillus - E. coli

35 Streptobacilli

36 Spirillum

37 Bacterial Kingdoms

38 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

39 Archaebacteria Subdivided into 3 groups:Subdivided into 3 groups: Methanogens Methanogens Thermoacidophiles Thermoacidophiles Extreme Halophiles Extreme Halophiles

40 Methanogens Live in anaerobic environments (no oxygen)Live in anaerobic environments (no oxygen) Get energy by changing H 2 & CO 2 into methane gasGet energy by changing H 2 & CO 2 into methane gas Found in swamps, sewage treatment plants, digestive tracts of animalsFound in swamps, sewage treatment plants, digestive tracts of animals

41 Methanogens Break down cellulose in a cow’s stomachBreak down cellulose in a cow’s stomach Produce marsh (methane) gasProduce marsh (methane) gas

42 Extreme Halophiles Live in very salty waterLive in very salty water Use salt to generate ATP (energy)Use salt to generate ATP (energy) Dead Sea, Great Salt Lake inhabitantsDead Sea, Great Salt Lake inhabitants

43 Thermoacidophiles or Thermophiles Live in extremely hot environmentsLive in extremely hot environments Found in volcanic vents, hot springs, cracks on ocean floor that leak acidFound in volcanic vents, hot springs, cracks on ocean floor that leak acid

44 Kingdom Eubacteria True Bacteria

45 Cyanobacteria Gram negativeGram negative PhotosyntheticPhotosynthetic Called blue-green bacteriaCalled blue-green bacteria Contain phycocyanin (red- blue) pigments & chlorophyllContain phycocyanin (red- blue) pigments & chlorophyll

46 Cyanobacteria

47 Nutrition, Respiration, and Reproduction

48 Modes of Nutrition 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

49 Methods of Respiration Obligate Aerobes – require O 2 (tuberculosis bacteria)Obligate Aerobes – require O 2 (tuberculosis bacteria) Obligate Anaerobes – die if O 2 is present (tetanus)Obligate Anaerobes – die if O 2 is present (tetanus) Facultative Anaerobes – don’t need O 2, but aren’t killed by it (E. coli)Facultative Anaerobes – don’t need O 2, but aren’t killed by it (E. coli)

50 Bacterial Respiration Anaerobes carry on fermentationAnaerobes carry on fermentation Aerobes carry on cellular respirationAerobes carry on cellular respiration

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

52 Binary Fission E. coli

53 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

54 Conjugation

55 Spore Formation Form endospore whenever when habitat conditions become harsh (little food)Form endospore whenever when habitat conditions become harsh (little food) Able to survive for long periods of time as endospermAble to survive for long periods of time as endosperm Difficult to destroy (heat resistant)Difficult to destroy (heat resistant)

56 Transduction & Transformation Genetically change bacteriaGenetically change bacteria May become antibiotic resistantMay become antibiotic resistant Transformed bacteria pick up pieces of DNA from dead bacterial cellsTransformed bacteria pick up pieces of DNA from dead bacterial cells Transduction – viruses carry foreign DNA to bacteria; used to make insulinTransduction – viruses carry foreign DNA to bacteria; used to make insulin

57 Pathenogenic Bacteria

58 Pathogens Called germs or microbesCalled germs or microbes Cause diseaseCause disease May produce poisons or toxinsMay produce poisons or toxins Endotoxins released after bacteria die (E. coli)Endotoxins released after bacteria die (E. coli) Exotoxins released by Gram + bacteria (C. tetani)Exotoxins released by Gram + bacteria (C. tetani)