PowerPoint PresentationSlide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Slide 42Slide 43Slide 44Slide 45Slide 46Slide 47Slide 48Slide 49Slide 50Slide 51Slide 52Slide 53Slide 54Slide 55Slide 56Slide 57Slide 58Slide 59Functional Anatomy of Prokaryotic and Eukaryotic 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: Pearson Benjamin Cummings, 2004, 2007, 2010.General Comparisons(on handout)ProkaryoteEukaryoteThe 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 plane resulting in characteristic arrangements(arrangements on handout)Cocci-single coccus: daughter cells separate-diplococcus: 2, flat on adjacent sides-streptococci: chain, all cells divide in same plane-tetrad: 4, division occurs in two planes-sarcinae: 8, division occurs in three planes-staphylococci: group, cluster, cells divide in random planesBacilli-rods of various length: oval to “hot dog”-rods divide only along the short axis-single bacillus: daughter cells separate-diplobacilli: 2-streptobacilli: chain-coccobacillus: short oval, often confused with cocci (cocci are perfectly spherical, any ovalish shape = bacillus)Spiral-one or more twists-vibrio: curved rod-spirillum: rigid helical shape, move via flagella-spirochete: flexible helical shape, move via axial filamentsMost bacteria are monomorphic: always one shapeSome are genetically pleomorphic: have varied shapes within the population of a single speciesStructure of the Prokaryotic Cell(general cell on handout)*Not all cells have all structures!1). Glycocalyxglycocalyx = external, outermost surface layer of secreted carbohydrate-rich gelatinous material, usually sticky or slimycapsule = organized glycocalyx, firmly attached to cell wallslime layer = unorganized glycocalyx, loosely attached to cell wallglycocalyx functions:-promote biofilm formation-allow cell adhesion to substrate or 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)2). 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 cell-structure:(handout)a. filament: -made up of intertwined chains of flagellin protein-hollow core-sticks out beyond plasma 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)Salmonella monotrichous flagellaPlay SalmonellaFlagella.movFlagella MovementsPlay flagella_movement.swfQuickTime™ and aCinepak decompressorare needed to see this picture.3). Axial Filaments-a.k.a. endoflagella-used by spirochetes for taxis-consist of flagella-like structures wound around spirocheteunder the outer sheath-rotation of filaments produces cork-screw rotation of sheath and thus whole spirochete-rotation allows penetration of secretions and tissues4). Fimbriae and Pili-short, hair-like appendages-composed of pilin proteinFimbriae: -at poles or all over surface-up to few hundred per cell-“fuzzy” coat used for adherencePili/Pilus:-usually one, if present-used to transfer DNA to neighboring cell (“conjugation/sex pilus”)-more rarely, some types used for movement via pilus retraction*twitching motilityshort, jerky*gliding motilitythrough biofilms5). 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 by two monosaccharides linked end to end:NAG (N-acetylglucosmine)NAM (N-acetylmuramic acid)-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)2. 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 acid-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, heavy metals, dyes, etc.-LPS is toxic to animals (Lipid A portion)causes endotoxic shockUnusual wall structures1. Mycobacterium species: -Gram+ structure with mycolic acids- (waxy) resists dehydration2. Mycoplasma species:-smallest bacteria-no cell wall-have sterols in membrane (resist osmotic lysis)3. Archaea-either no walls or-walls consisting of pseudomurein (different carbohydrate)-Many antimicrobial drugs target bacterial cell walls: -safe target, chemical structure not found in animalse.g. Penicillin: prevents peptide crosslinking, prevents formation of functional wall in growing cellse.g. Lysozyme: -enzyme produced by some eukaryotes-found in human secretions-digests the NAG-NAM linkages-weak wall = osmotic cell lysis-most effective against Gram+ (outer membrane protects Gram-)Penicillin effects on growing BacillusQuickTime™ and aYUV420 codec decompressorare needed to see this picture.Play CellLysis.mpg6). Plasma Membrane / Cell Membrane