Chapter 3PowerPoint PresentationMorphology of Prokaryotic CellsSlide 4Slide 5Slide 6Slide 7Slide 8Slide 9Layers External to Cell WallSlide 11FlagellaSlide 13Slide 14Axial filamentsAttachment ProteinsSlide 17Prokaryotic Cell WallSlide 19Slide 20Slide 21Slide 22GRAM STAININGSlide 24Slide 25Summary of Gram + vs. Gram –Atypical cell wallSlide 28Slide 29Structures Internal to Cell WallSlide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Internal StructuresSlide 43Slide 44Slide 45Slide 46Slide 47Slide 48Slide 49Chapter 3Chapter 3Functional Anatomy of Prokaryotic Functional Anatomy of Prokaryotic and Eukaryotic Cellsand Eukaryotic CellsProkaryotes can be grouped based on morphology Genetically determinedMonomorphic vs pleomorphicSize Range 0.2 to 80 um in diameter2 to 600 um in lengthAverage size: 0.2 -1.0 µm × 2 - 8 µmMorphology of Prokaryotic CellsMorphology of Prokaryotic CellsProkaryotes exhibit a Prokaryotes exhibit a variety of shapesvariety of shapesMost common Most commonSpiralSpiralUncommon ShapesUncommon ShapesStellaHaloarculaCells may form groupingsCells may form groupingsCells adhere together after division Cells adhere together after division Form characteristic arrangementsForm characteristic arrangementsDepends on plan of divisionDepends on plan of divisionNeisseriaNeisseria EEnterococcusnterococcus MicrococcusMicrococcus Sarcina Sarcina Staphylococcus aureusStaphylococcus aureusBacillus anthracis Bacillus anthracis Bacillus megateriumBacillus megaterium Bordetella pertussisBordetella pertussisLayers External to Cell WallLayers External to Cell WallGlycocalyxGlycocalyxMade inside the cell; excreted to surfaceMade inside the cell; excreted to surfaceGeneral functionsGeneral functionsProtectionProtectionAttachmentAttachmentMotility MotilityCapsule or Slime LayerCapsule or Slime LayerChemical composition varies Chemical composition varies depending on speciesdepending on speciesFlagellaFlagellaNaked filaments composed of flagellin Naked filaments composed of flagellin Rotate clockwise/counterclockwise Rotate clockwise/counterclockwise Runs and tumblesRuns and tumblesTaxisTaxisFlagella structure has Flagella structure has three basic partsthree basic partsFilamentFilamentHookHookBasal bodyBasal bodyPolar - MonotrichousPolar - MonotrichousPeritrichousPeritrichousPolar -LophotrichousPolar -LophotrichousPolar -amphitrichousPolar -amphitrichousAxial filamentsAxial filaments Bundles of endoflagella that spiral around cellBundles of endoflagella that spiral around cellSpirochete bacteria onlySpirochete bacteria onlyCorkscrew motion Corkscrew motionAttachment ProteinsAttachment ProteinsFimbriae - bacteriaFimbriae - bacteriaFilaments of pilin proteinFilaments of pilin proteinAttachment Attachment Hami – archaeaHami – archaeaHooked protein filamentHooked protein filamentAttachmentAttachmentSex PiliSex PiliPilin tubules Pilin tubules Exchange of DNA Exchange of DNA•Cannulae – thermophilic archaea Cannulae – thermophilic archaea •Spinae - marine bacteria Spinae - marine bacteria •Connect cells over distancesConnect cells over distances•Creates mesh-like network Creates mesh-like networkProkaryotic Prokaryotic Cell WallCell WallDetermines shape of cellDetermines shape of cellProtects from osmotic pressure Protects from osmotic pressure Anchor point for flagella Anchor point for flagella Contributes to virulence Contributes to virulenceUnique chemical structureUnique chemical structureBacteria vs. ArchaeaBacteria vs. ArchaeaGram positive vs. Gram-negativeGram positive vs. Gram-negativePeptidoglycan (PTG) (murein)Peptidoglycan (PTG) (murein)Sugar found only in bacteria Sugar found only in bacteria Archaea may have proteins or alternate sugarsArchaea may have proteins or alternate sugarsBasic structure of PTGBasic structure of PTGDisaccharide polymer Disaccharide polymer N-acetylglucosamin (NAG)N-acetylglucosamin (NAG)N-acetylmuramic acid (NAM)N-acetylmuramic acid (NAM)Glycan chain held together by Glycan chain held together by amino acidsamino acidsTetrapeptide chainTetrapeptide chainProtein crossbridges may or may Protein crossbridges may or may not be present not be present Mostly G+Mostly G+Gram positive cell wallGram positive cell wallThick layer of PTGThick layer of PTGTeichoic acidsTeichoic acidsLipoteichoic or Wall Lipoteichoic or Wall teichoic acidsteichoic acidsPolyalcohols that provide Polyalcohols that provide antigenic specificityantigenic specificityMay have external May have external protein or sugar layerprotein or sugar layerGram-negative cell wallGram-negative cell wallLittle or no PTGLittle or no PTGOuter lipopolysaccharide Outer lipopolysaccharide membrane (LPS)membrane (LPS)O-specific polysaccharide O-specific polysaccharide side chainside chainLipid A endotoxin Lipid A endotoxin Significant periplasmic Significant periplasmic spacespaceGRAM STAININGGRAM STAININGGram-positive and gram-negative bacteria can be Gram-positive and gram-negative bacteria can be identified using a “gram stain”identified using a “gram stain”Summary of Gram + vs. Gram – Summary of Gram + vs. Gram – G+ cell G+ cell many rigid layers of peptidoglycanmany rigid layers of peptidoglycanteichoic acidsteichoic acidsNo outer LPS membrane No outer LPS membrane 2 ring basal body anchoring flagella2 ring basal body anchoring flagellaG- cell G- cell Little or no peptidoglycanLittle or no peptidoglycanno teichoic acidsno teichoic acidsLPS outer membraneLPS outer membrane4 ring basal body anchoring flagella4 ring basal body anchoring flagellaAtypical cell wallAtypical cell wallAcid-fast cell wallsAcid-fast cell wallsClassified as gram-positiveClassified as gram-positivemycolic acidmycolic acid bound to PTG bound to PTGMycobacteriumMycobacteriumNocardiaNocardiaChlamydiaChlamydia Classified as Gram – with Classified as Gram – with no PTGno PTGcysteine-rich proteins cysteine-rich proteinsNo cell wall No cell wall MycoplasmasMycoplasmasSterols in plasma membraneSterols in plasma membraneStructures Structures InternalInternal to Cell Wall to Cell WallCytoplasmic membraneCytoplasmic membraneDelicate thin fluid structureDelicate thin
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