Functional Anatomy of Prokaryotic andEukaryotic Cells(Chapter 4)Lecture MaterialsforAmy Warenda Czura, Ph.D.Suffolk County Community CollegeEastern CampusPrimary Source for figures and content:Tortora, G.J. Microbiology An Introduction 8th, 9th, 10th ed. San Francisco: PearsonBenjamin Cummings, 2004, 2007, 2010.Amy Warenda Czura, Ph.D.1SCCC BIO244 Chapter 4 Lecture SlidesGeneral Comparisons(on handout)ProkaryoteEukaryoteAmy Warenda Czura, Ph.D.2SCCC BIO244 Chapter 4 Lecture SlidesThe Prokaryotic Cell-“pre-nucleus”-bacteria and archaeaSize, shape & arrangement:- 0.2-2.0µm diameter- 2-8 µm length- three shapes common:coccus = spherebacillus = rodspiral = twisted-division by binary fission:can result in daughter cells remaining loosely adhered along the division planeresulting in characteristic arrangements(arrangements on handout)Amy Warenda Czura, Ph.D.3SCCC BIO244 Chapter 4 Lecture SlidesCocci-single coccus: daughtercells separate-diplococcus: 2, flat onadjacent sides-streptococci: chain, allcells divide in sameplane-tetrad: 4, division occursin two planes-sarcinae: 8, division occursin three planes-staphylococci: group,cluster, cells dividein random planesAmy Warenda Czura, Ph.D.4SCCC BIO244 Chapter 4 Lecture SlidesBacilli-rods of various length:oval to “hot dog”-rods divide only alongthe short axis-single bacillus: daughtercells separate-diplobacilli: 2-streptobacilli: chain-coccobacillus: short oval,often confused with cocci(cocci are perfectly spherical,any ovalish shape = bacillus)Amy Warenda Czura, Ph.D.5SCCC BIO244 Chapter 4 Lecture SlidesSpiral-one or more twists-vibrio: curved rod-spirillum: rigid helical shape,move via flagella-spirochete: flexible helicalshape, move viaaxial filamentsMost bacteria are monomorphic:always one shapeSome are genetically pleomorphic: have varied shapes within the population of a single speciesAmy Warenda Czura, Ph.D.6SCCC BIO244 Chapter 4 Lecture SlidesStructure of the Prokaryotic Cell(general cell on handout)*Not all cells have all structures!1). Glycocalyxglycocalyx = external, outermostsurface layer of secreted carbohydrate-richgelatinous material, usually sticky or slimycapsule = organized glycocalyx, firmly attached to cell wallslime layer = unorganized glycocalyx, looselyattached to cell wallglycocalyx functions:-promote biofilm formation-allow cell adhesion to substrateor host tissues-protect cell from dehydration-protect cell from nutrient loss-protect cell from phagocytosis(capsules are required for some pathogenic bacterial to be virulent)(virulence = ability to cause disease)Amy Warenda Czura, Ph.D.7SCCC BIO244 Chapter 4 Lecture Slides2). Flagella-long, filamentous appendages-used for motility-arrangements:1. monotrichous:one on one end2. amphitrichous:one or more on each end3. lophotrichous:two or more on one end4. peritrichous:all over cellAmy Warenda Czura, Ph.D.8SCCC BIO244 Chapter 4 Lecture Slides-structure:(handout)a. filament:-made up ofintertwinedchains offlagellinprotein-hollow core-sticks outbeyondplasma membrane and cell wallb. hook:-provides rotational movement of flagella-solid, composed of hook proteinc. basal body:-rod and disc structure-anchors flagellum to cell wallflagellum rotates to cause taxis of bacteriataxis = movement, usually toward or away from a stimulus (chemotaxis, phototaxis)Amy Warenda Czura, Ph.D.9SCCC BIO244 Chapter 4 Lecture SlidesSalmonella monotrichous flagellaPlay SalmonellaFlagella.movFlagella MovementsPlay flagella_movement.swfAmy Warenda Czura, Ph.D.10SCCC BIO244 Chapter 4 Lecture Slides3). Axial Filaments-a.k.a. endoflagella-used by spirochetes for taxis-consist of flagella-like structureswound around spirocheteunder the outer sheath-rotation of filaments produces cork-screw rotation of sheath and thus whole spirochete-rotation allows penetration of secretions andtissuesAmy Warenda Czura, Ph.D.11SCCC BIO244 Chapter 4 Lecture Slides4). Fimbriae and Pili-short, hair-like appendages-composed of pilin proteinFimbriae:-at poles or all oversurface-up to few hundredper cell-“fuzzy” coat usedfor adherenceAmy Warenda Czura, Ph.D.12SCCC BIO244 Chapter 4 Lecture SlidesPili/Pilus:-usually one, if present-used to transfer DNA to neighboring cell(“conjugation/sex pilus”)-more rarely, some types used for movementvia pilus retraction*twitching motilityshort, jerky*gliding motilitythrough biofilmsAmy Warenda Czura, Ph.D.13SCCC BIO244 Chapter 4 Lecture Slides5). Cell Wall-located outside the cell/plasma membrane-gives cell its shape-provides protection-resists osmotic lysis-provides anchorage point for flagellacomposition:-in bacteria = peptidoglycan (aka murein):-lattice of disaccharides and polypeptides-repeating disaccharide chains formed bytwo monosaccharides linked end to end:NAG (N-acetylglucosmine)NAM (N-acetylmuramic acid)Amy Warenda Czura, Ph.D.14SCCC BIO244 Chapter 4 Lecture Slides-disaccharide chains are held together by polypeptides to form a tight wall (handout)-Two common cell wall types in bacteria:can be distinguished by a staining procedure (Gram’s Stain)(handout)1. Gram Positive Cell Walls-thick, many layers of peptidoglycan, strong, rigid-also contain teichoic acids (neg. charge, may regulate cation movement)Amy Warenda Czura, Ph.D.15SCCC BIO244 Chapter 4 Lecture Slides2. Gram Negative Cell Wall-has an outer membrane-periplasmic space between outer membrane and cell membrane houses the peptidoglycan in periplasm-few layers of peptidoglycan, thinner, weaker-no teichoic acid*G-wall = outer membrane + thin peptidogycan in periplasm*G+wall = thick peptidogycan + teichoic acidAmy Warenda Czura, Ph.D.16SCCC BIO244 Chapter 4 Lecture Slides-outer membrane:-composed of phospholipids, lipoproteins,and lipopolysaccharide (LPS)-has porins to allow exchange with environment-functions of outer membrane:-evade phagocytosis-avoid action of complement-chemical barrier: resist antibiotics, digestive enzymes, detergents, heavymetals, dyes, etc.-LPS is toxic to animals (Lipid A portion)causes endotoxic shockAmy Warenda Czura, Ph.D.17SCCC BIO244 Chapter 4 Lecture SlidesUnusual wall structures1. Mycobacterium species:-Gram+ structure with mycolic acids- (waxy) resists dehydration2. Mycoplasma species:-smallest bacteria-no cell wall-have sterols in membrane (resist osmoticlysis)3. Archaea-either no walls or-walls consisting of pseudomurein (different carbohydrate)Amy Warenda Czura, Ph.D.18SCCC BIO244 Chapter 4 Lecture Slides-Many antimicrobial drugs target bacterial cellwalls:-safe