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 Prokaryotic & Eukaryotic Cells

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

8 Classification of Life

9 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

10 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

11 Archaebacteria

12 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

13 Eubacteria

14 Characteristics of Bacteria

15 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

16 Bacterial Cell

17 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

18 Sticky Bacterial Capsule

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

21 Bacterial Structure Infoldings of cell membrane carry on photosynthesis & cellular respirationInfoldings of cell membrane carry on photosynthesis & cellular respiration Infoldings called MesosomesInfoldings called Mesosomes

22 Mesosomes MESOSOME

23 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

24 Staphylococcus Bacterial

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

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

27 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

28

29 Flagella Made of FlagellinMade of Flagellin Used for ClassificationUsed for Classification Monotrichous: 1 flagellaMonotrichous: 1 flagella Lophotrichous: tuft at one endLophotrichous: tuft at one end Amphitrichous: tuft at both endsAmphitrichous: tuft at both ends Peritrichous: all around bacteriaPeritrichous: all around bacteria

30 MonotrichousLophotrichous AmphitrichousPeritrichous

31 Question: What is this type of bacteria ?

32 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

33 Pili in Conjugation

34 Bacterial Shapes

35 Shapes Are Used to Classify Bacillus: Rod shapedBacillus: Rod shaped Coccus: Spherical (round)Coccus: Spherical (round) Vibrio: Comma shaped with flagellaVibrio: Comma shaped with flagella Spirillum: Spiral shapeSpirillum: Spiral shape Spirochete: wormlike spiral shapeSpirochete: wormlike spiral shape

36

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

38

39

40 Diplococcus

41 Streptococcus Causes Strep Throat

42 Staphylococcus

43 Bacillus - E. coli

44 Streptobacilli

45 Spirillum

46 Spirochetes

47 Leptospira

48

49 Bacterial Kingdoms

50 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

51 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

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

53 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

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

55 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

56 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

57 Kingdom Eubacteria True Bacteria

58 Characteristics 3 basic shapes (coccus, bacillus, spirilla)3 basic shapes (coccus, bacillus, spirilla) Most are heterotrophic (can’t make their own food)Most are heterotrophic (can’t make their own food) May be aerobic or anaerobicMay be aerobic or anaerobic Identified by Gram stainingIdentified by Gram staining

59 Gram Staining Developed in 1884 by Hans GramDeveloped in 1884 by Hans Gram Bacteria treated with purple Crystal Violet & red Safranin stainsBacteria treated with purple Crystal Violet & red Safranin stains Cell walls either stain purple or reddish pinkCell walls either stain purple or reddish pink

60 Gram Positive Have thick layer of peptidoglycan (protein-sugar complex)Have thick layer of peptidoglycan (protein-sugar complex) Single lipid layerSingle lipid layer Stain purpleStain purple Can be treated with antibioticsCan be treated with antibiotics

61 Gram Positive Bacteria Lactobacilli (makes yogurt & buttermilk) Lactobacilli (makes yogurt & buttermilk) Actinomycetes (make antibiotics) Actinomycetes (make antibiotics) Clostridium (lockjaw bacteria) Clostridium (lockjaw bacteria) Streptococcus (strep throat) Streptococcus (strep throat) Staphylococcus (staph infections) Staphylococcus (staph infections)

62 Gram Negative Bacteria Thin layer of peptidoglycan in cell wallThin layer of peptidoglycan in cell wall Extra thick layer of lipidsExtra thick layer of lipids Stain pink or reddishStain pink or reddish Hard to treat with antibioticsHard to treat with antibiotics Some photosynthetic but make sulfur not oxygenSome photosynthetic but make sulfur not oxygen Some fix nitrogen for plantsSome fix nitrogen for plants

63 Gram Negative Rhizobacteria grow in root nodules of legumes (soybeans, peanuts)Rhizobacteria grow in root nodules of legumes (soybeans, peanuts) Fix N 2 from air into usable ammoniaFix N 2 from air into usable ammonia

64 Gram Negative Rickettsiae are parasitic bacteria carried by ticksRickettsiae are parasitic bacteria carried by ticks Cause Lyme disease & Rocky Mountain Spotted FeverCause Lyme disease & Rocky Mountain Spotted Fever

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

66 Cyanobacteria May be red, yellow, brown, black, or blue-greenMay be red, yellow, brown, black, or blue-green May grow in chains (Oscillatoria)May grow in chains (Oscillatoria) Have Heterocysts to help fix N 2Have Heterocysts to help fix N 2 First to re-enter devastated areasFirst to re-enter devastated areas Some cause Eutrophication (use up O2 when die & decompose in water)Some cause Eutrophication (use up O2 when die & decompose in water)

67 Cyanobacteria

68 Spirochetes Gram positiveGram positive Flagella at each endFlagella at each end Move in corkscrew motionMove in corkscrew motion Some aerobic; others anaerobicSome aerobic; others anaerobic May be free living, parasitic, or symbioticMay be free living, parasitic, or symbiotic

69 Enteric Bacteria Gram negativeGram negative Can live in aerobic & anaerobic habitatsCan live in aerobic & anaerobic habitats Includes E. coli in intestinesIncludes E. coli in intestines Salmonella – causes food poisoningSalmonella – causes food poisoning

70 Chemoautotrophs Gram negativeGram negative Obtain energy from minerals like ironObtain energy from minerals like iron Found in freshwater pondsFound in freshwater ponds

71 Nutrition, Respiration, and Reproduction

72 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

73 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)

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

75 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)

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

77 Binary Fission E. coli

78 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

79 Conjugation

80 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)

81 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

82 Pathenogenic Bacteria

83 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)

84