Structure of bacteria1
- 1. 1 BacteriaBacteria Structure and FunctionStructure and Function
- 3. 3 Cellular EvolutionCellular Evolution • Current evidenceCurrent evidence indicates thatindicates that eukaryoteseukaryotes evolved from prokaryotesevolved from prokaryotes between 1 and 1.5 billionbetween 1 and 1.5 billion years agoyears ago • Two theories:Two theories: 1.1. Infolding theoryInfolding theory 2.2. Endosymbiotic theoryEndosymbiotic theory
- 4. 4 Infolding TheoryInfolding Theory • TheThe infolding of theinfolding of the prokaryotic plasmaprokaryotic plasma membrane gave rise tomembrane gave rise to eukaryotic organelles.eukaryotic organelles. infolding organelle
- 5. 5 Endosymbiotic TheoryEndosymbiotic Theory • Endosymbiosis refers toEndosymbiosis refers to oneone species living within anotherspecies living within another(the(the host)host) • Movement ofMovement of smallersmaller photosyntheticphotosynthetic && heterotrophicheterotrophic prokaryotesprokaryotes into larger prokaryoticinto larger prokaryotic host cellshost cells • FormedFormed cell organellescell organelles chloroplast mitochondria
- 6. 6 Prokaryotic &Prokaryotic & Eukaryotic CellsEukaryotic Cells
- 7. 7 EarliestEarliest ProkaryotesProkaryotes • Most numerousMost numerous organisms on Earth • Include all bacteriabacteria • Earliest fossilsEarliest fossils datedate 2.5 billion years old
- 9. 9 Three Domains ofThree Domains of LifeLife • ArchaeaArchaea –– prokaryotes living inprokaryotes living in extreme habitatsextreme habitats • BacteriaBacteria-- Cyanobacteria andCyanobacteria and eubacteriaeubacteria • EukaryaEukarya –– Protozoans, fungi,Protozoans, fungi, plants, & animalsplants, & animals
- 10. 10 Kingdoms of BacteriaKingdoms of Bacteria Archaebacteria:Archaebacteria: Found inFound in harshharsh environmentsenvironments UnderseaUndersea volcanic ventsvolcanic vents,, acidicacidic hot springshot springs,, saltysalty waterwater
- 12. 12 Kingdoms of BacteriaKingdoms of Bacteria Eubacteria:Eubacteria: Called theCalled the truetrue bacteriabacteria Most bacteriaMost bacteria are inare in this groupthis group Include photosyntheticInclude photosynthetic CyanobacteriaCyanobacteria
- 15. 15 Bacterial StructureBacterial Structure • MicroscopicMicroscopic prokaryotesprokaryotes • NoNo nucleus or membrane-nucleus or membrane- bound organellesbound organelles • ContainContain ribosomesribosomes • Single, circularSingle, circular chromosome inchromosome in nucleoidnucleoid regionregion
- 17. 17 ProtectionProtection • Cell Wall made ofCell Wall made of PeptidoglycanPeptidoglycan • May have a stickyMay have a sticky coating called thecoating called the CapsuleCapsule forfor attachment to host orattachment to host or other bacteriaother bacteria
- 19. 19 BacterialBacterial StructureStructure • Have small rings ofHave small rings of DNA calledDNA called PlasmidsPlasmids • UnicellularUnicellular • SmallSmall in size (0.5 toin size (0.5 to 2μm)2μm) PLASMIDSPLASMIDS
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- 21. 21 Bacterial StructureBacterial Structure • InfoldingsInfoldings of cellof cell membrane carry onmembrane carry on photosynthesis &photosynthesis & cellular respirationcellular respiration • Infoldings calledInfoldings called MesosomesMesosomes
- 23. 23 Bacterial StructureBacterial Structure • Most grow best atMost grow best at pH of 6.5 to 7.0pH of 6.5 to 7.0 • Many act asMany act as decomposersdecomposers recyclingrecycling nutrientsnutrients • Some causeSome cause diseasedisease
- 25. 25 Useful BacteriaUseful Bacteria • SomeSome bacteriabacteria cancan degrade oildegrade oil • Used toUsed to clean upclean up oiloil spillsspills
- 26. 26 Useful BacteriaUseful Bacteria • Other usesOther uses for bacteriafor bacteria includeinclude makingmaking yogurt,yogurt, cheese, andcheese, and buttermilk.buttermilk.
- 27. 27 FlagellaFlagella • Bacteria thatBacteria that areare motilemotile havehave appendagesappendages calledcalled flagellaflagella • Attached byAttached by Basal BodyBasal Body • A bacteria canA bacteria can havehave one orone or manymany flagellaflagella
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- 29. 29 FlagellaFlagella • Made ofMade of FlagellinFlagellin • Used forUsed for ClassificationClassification • Monotrichous:Monotrichous: 1 flagella1 flagella • Lophotrichous:Lophotrichous: tuft attuft at one endone end • Amphitrichous:Amphitrichous: tuft attuft at both endsboth ends • Peritrichous:Peritrichous: all aroundall around bacteriabacteria
- 31. 31 Question:Question: What is this type ofWhat is this type of bacteria ?bacteria ?
- 32. 32 PiliPili • Short proteinShort protein appendagesappendages • SmallerSmaller than flagellathan flagella • AdhereAdhere bacteria tobacteria to surfacessurfaces • Used inUsed in conjugationconjugation forfor Exchange of geneticExchange of genetic informationinformation • AidAid FlotationFlotation byby increasing buoyancyincreasing buoyancy
- 33. 33 Pili in ConjugationPili in Conjugation
- 35. 35 Shapes Are Used toShapes Are Used to ClassifyClassify • Bacillus:Bacillus: Rod shapedRod shaped • Coccus:Coccus: Spherical (round)Spherical (round) • Vibrio:Vibrio: Comma shaped withComma shaped with flagellaflagella • Spirillum:Spirillum: Spiral shapeSpiral shape • Spirochete:Spirochete: wormlikewormlike spiral shapespiral shape
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- 37. 37 Grouping of BacteriaGrouping of Bacteria • DiploDiplo- Groups of- Groups of twotwo • StreptoStrepto- chains- chains • StaphyloStaphylo- Grapelike- Grapelike clustersclusters
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- 41. 41 Streptococcus CausesStreptococcus Causes Strep ThroatStrep Throat
- 43. 43 Bacillus -Bacillus - E. coliE. coli
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- 50. 50 ArchaebacteriaArchaebacteria • Lack peptidoglycanLack peptidoglycan in cellin cell wallswalls • HaveHave different lipidsdifferent lipids inin their cell membranetheir cell membrane • Different types ofDifferent types of ribosomesribosomes • VeryVery different genedifferent gene sequencessequences
- 51. 51 ArchaebacteriaArchaebacteria • Archaebacteria can live inArchaebacteria can live in extremely harshextremely harsh environmentsenvironments • TheyThey do not require oxygendo not require oxygen and can live inand can live in extremelyextremely saltysalty environments as well asenvironments as well as extremely hotextremely hot environmentsenvironments • Called theCalled the Ancient bacteriaAncient bacteria
- 52. 52 ArchaebacteriaArchaebacteria • Subdivided into 3Subdivided into 3 groups:groups: MethanogensMethanogens ThermoacidophilesThermoacidophiles Extreme HalophilesExtreme Halophiles
- 53. 53 MethanogensMethanogens • Live inLive in anaerobicanaerobic environments (no oxygen)environments (no oxygen) • Get energy byGet energy by changing Hchanging H22 & CO& CO22 into methane gasinto methane gas • Found inFound in swampsswamps,, sewagesewage treatmenttreatment plants,plants, digestivedigestive tractstracts of animalsof animals
- 54. 54 MethanogensMethanogens • Break downBreak down cellulose in acellulose in a cow’scow’s stomachstomach • ProduceProduce marshmarsh (methane)(methane) gasgas
- 55. 55 Extreme HalophilesExtreme Halophiles • Live in veryLive in very salty watersalty water • UseUse salt tosalt to generategenerate ATPATP (energy)(energy) • Dead Sea,Dead Sea, Great SaltGreat Salt LakeLake inhabitantsinhabitants
- 56. 56 Thermoacidophiles orThermoacidophiles or ThermophilesThermophiles • Live inLive in extremely hotextremely hot environmentsenvironments • Found inFound in volcanicvolcanic vents,vents, hot springs,hot springs, cracks on oceancracks on ocean floor that leakfloor that leak acidacid
- 58. 58 CharacteristicsCharacteristics • 3 basic shapes3 basic shapes (coccus,(coccus, bacillus, spirilla)bacillus, spirilla) • Most areMost are heterotrophicheterotrophic (can’t make their own food)(can’t make their own food) • May beMay be aerobic oraerobic or anaerobicanaerobic • Identified byIdentified by Gram stainingGram staining
- 59. 59 Gram StainingGram Staining • Developed inDeveloped in 1884 by1884 by Hans GramHans Gram • Bacteria treated withBacteria treated with purple Crystal Violet & redpurple Crystal Violet & red Safranin stainsSafranin stains • Cell wallsCell walls either staineither stain purple or reddish pinkpurple or reddish pink
- 60. 60 Gram PositiveGram Positive • HaveHave thick layerthick layer of peptidoglycanof peptidoglycan (protein-sugar(protein-sugar complex)complex) • Single lipidSingle lipid layerlayer • StainStain purplepurple • Can be treatedCan be treated withwith antibioticsantibiotics
- 61. 61 Gram PositiveGram Positive BacteriaBacteria LactobacilliLactobacilli (makes yogurt &(makes yogurt & buttermilk)buttermilk) Actinomycetes (Actinomycetes (makemake antibiotics)antibiotics) ClostridiumClostridium (lockjaw bacteria)(lockjaw bacteria) StreptococcusStreptococcus (strep throat)(strep throat) Staphylococcus (Staphylococcus (staphstaph infections)infections)
- 62. 62 Gram NegativeGram Negative BacteriaBacteria • Thin layer of peptidoglycanThin layer of peptidoglycan inin cell wallcell wall • ExtraExtra thick layer of lipidsthick layer of lipids • StainStain pink or reddishpink or reddish • Hard to treatHard to treat with antibioticswith antibiotics • SomeSome photosyntheticphotosynthetic butbut make sulfur not oxygenmake sulfur not oxygen • SomeSome fix nitrogenfix nitrogen for plantsfor plants
- 63. 63 Gram NegativeGram Negative • RhizobacteriaRhizobacteria grow in rootgrow in root nodules ofnodules of legumeslegumes (soybeans,(soybeans, peanuts)peanuts) • Fix NFix N22 from airfrom air into usableinto usable ammoniaammonia
- 64. 64 Gram NegativeGram Negative • RickettsiaeRickettsiae areare parasiticparasitic bacteria carriedbacteria carried by ticksby ticks • CauseCause LymeLyme disease & Rockydisease & Rocky MountainMountain Spotted FeverSpotted Fever
- 65. 65 CyanobacteriaCyanobacteria • GramGram negativenegative • PhotosyntheticPhotosynthetic • CalledCalled blue-green bacteriablue-green bacteria • ContainContain phycocyaninphycocyanin (red-(red- blue) pigments &blue) pigments & chlorophyllchlorophyll
- 66. 66 CyanobacteriaCyanobacteria • May be red, yellow, brown, black,May be red, yellow, brown, black, or blue-greenor blue-green • May grow inMay grow in chainschains ((OscillatoriaOscillatoria)) • HaveHave HeterocystsHeterocysts to help fix Nto help fix N22 • First to re-enterFirst to re-enter devastateddevastated areasareas • Some causeSome cause EutrophicationEutrophication (use up(use up O2 when die & decompose inO2 when die & decompose in water)water)
- 68. 68 SpirochetesSpirochetes • GramGram positivepositive • Flagella at each endFlagella at each end • Move inMove in corkscrewcorkscrew motionmotion • SomeSome aerobicaerobic;; othersothers anaerobicanaerobic • May beMay be free living,free living, parasitic, orparasitic, or symbioticsymbiotic
- 69. 69 Enteric BacteriaEnteric Bacteria • GramGram negativenegative • Can live inCan live in aerobic &aerobic & anaerobicanaerobic habitatshabitats • IncludesIncludes E. coliE. coli inin intestinesintestines • SalmonellaSalmonella –– causes foodcauses food poisoningpoisoning
- 70. 70 ChemoautotrophsChemoautotrophs • GramGram negativenegative • Obtain energy fromObtain energy from minerals like ironminerals like iron • Found inFound in freshwaterfreshwater pondsponds
- 72. 72 Modes of NutritionModes of Nutrition • SaprobesSaprobes – feed on dead– feed on dead organic matterorganic matter • ParasitesParasites – feed on a host– feed on a host cellcell • PhotoautotrophPhotoautotroph – use– use sunlight to make foodsunlight to make food • ChemoautotrophChemoautotroph – oxidize– oxidize inorganic matter such asinorganic matter such as iron or sulfur to make foodiron or sulfur to make food
- 73. 73 Methods of RespirationMethods of Respiration • Obligate AerobesObligate Aerobes – require O– require O22 (tuberculosis bacteria)(tuberculosis bacteria) • Obligate AnaerobesObligate Anaerobes – die if– die if OO22 is present (tetanus)is present (tetanus) • Facultative AnaerobesFacultative Anaerobes – don’t– don’t need Oneed O22, but aren’t killed by, but aren’t killed by it (it (E. coliE. coli))
- 74. 74 Bacterial RespirationBacterial Respiration • AnaerobesAnaerobes carry oncarry on fermentationfermentation • AerobesAerobes carry oncarry on cellularcellular respirationrespiration
- 75. 75 ReproductionReproduction • Bacteria reproduceBacteria reproduce asexually by binary fissionasexually by binary fission • Single chromosomeSingle chromosome replicatesreplicates & then cell& then cell dividesdivides • RapidRapid • All new cellsAll new cells identicalidentical (clones)(clones)
- 76. 76 Cellular organism copies it’s genetic informationCellular organism copies it’s genetic information then splits into two identical daughter cellsthen splits into two identical daughter cells
- 77. 77 Binary FissionBinary Fission E. coliE. coli
- 78. 78 ReproductionReproduction • Bacteria reproduceBacteria reproduce sexually by Conjugationsexually by Conjugation • Form aForm a tube between 2tube between 2 bacteriabacteria to exchangeto exchange genetic materialgenetic material • Held together byHeld together by pilipili • New cellsNew cells NOT identicalNOT identical
- 80. 80 Spore FormationSpore Formation • FormForm endosporeendospore whenever whenwhenever when habitat conditionshabitat conditions becomebecome harshharsh (little food)(little food) • Able toAble to survive forsurvive for long periods oflong periods of timetime as endospermas endosperm • Difficult toDifficult to destroy (heatdestroy (heat resistant)resistant)
- 81. 81 Transduction &Transduction & TransformationTransformation • Genetically changeGenetically change bacteriabacteria • May becomeMay become antibiotic resistantantibiotic resistant • Transformed bacteriaTransformed bacteria pick uppick up pieces of DNA from deadpieces of DNA from dead bacterial cellsbacterial cells • TransductionTransduction – viruses carry– viruses carry foreign DNA to bacteria;foreign DNA to bacteria; usedused to make insulinto make insulin
- 83. 83 PathogensPathogens • CalledCalled germs or microbesgerms or microbes • CauseCause diseasedisease • May produceMay produce poisons orpoisons or toxinstoxins • EndotoxinsEndotoxins released afterreleased after bacteria die (bacteria die (E. coliE. coli)) • ExotoxinsExotoxins released by Gramreleased by Gram + bacteria (+ bacteria (C. tetaniC. tetani))
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