Exam 2 PowerPoints and Study Guide
Exam 2 PowerPoints and Study Guide 81382 - MICR 3050 - 001
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Bacterial Cell Structure and Function Size Shape and Arrangemen o 393 o Coccus e quoti x cocci and bacilli rod shaped most common 333 quot339 I I a prokaryotes n I arrangement Eg Spirillum determlned by plane of division and degree of separation after they divide Spirochete some don t completely Buddirzlg SLOT V 395 appen age a 1 lelde bacteria Stalk Hypha iii O h SlZC Filamentous varleS bacteria Figure 41 1 Brock Biology of Microorganisms 1 We 2006 Pearson Prentice Hall Inc t E CanaleParola Norbert Pfennig Norbert Pfennig Norbert Pfennig Norbert Pfennig r 0 Brock cocci s coccus spheres Cocci Copyright The McGrawHill Companies Inc Permission required for reproduction or display diplococci s diplococcus pairs 0 Like Where they don t completely separate in division Photo Researchers Inc Copyright The McGrawHill Companies Inc Permission required for reproduction or display streptococci chains staphylococci grapelike clusters tetrads 4 cocci in a square sarcinae cubic configuration of 8 cocci Bruce Iverson Copyright The McGrawHill Companies Inc Permission required for reproduction or display Bacilli bacilli s bacillus rods coccobacilli very short rods Copyright The McGraw F n Eaihb hi fi fr gsi h39rEci F dAror reproduction or display Vibrios resemble rods comma shaped 1 39 Centers for Disease Control Copyright The McGrawHill Companies Inc Permission required for reproduction or display spirilla s spirillum rigid helices spirochetes exible helices 039 lF39 Icg H c Leptospira interrogans a spirochete CDCNClDlHlPJanice Carr Other Shapes and Arrangements lamentous mycelium network of long multicellular laments pleomorphic Variable in shape Usually happens because there isn t a cell wall so it s more exible Archaea pleomorphic branched at square other unique shapes Copyright The McGrawHill Companies Inc Permission required for reproduction or display he M G quotquot39 39 mm 39quot 39 F mss m quotmm 39 39ep39 39 may e Hyphomcrobium d Streptomyces a filamentous bacterium Dr Amy Gehring The Shorter Bergey39s Manual of Belemquotnative Bacteriology Be John G Holt Editor lBergey39s Manual Trust Published by Vl lliarns 8 Wilkins Baltimore MD Copyright The McGrawHill Companies Inc Permission required for reproduction or display PV 9h PThe MCG39WH39quot mgtanies quot 0 Pem iSS Oquot requi39ed f P quotUC quot O G Sp39ay 3933 f Thermoproteus tenax a branched archaeal cell From JT Staley MP Bryant N Pfenning and JG Holt Eds Bergey39s Manual of Systematic Bacteriology Vol 3 1989 Mlliams and Mlkins Co Baltimore Robinson Dept of Micro U of Cal LA From Walther Stoeckenius Walsby39s Square Bacterium Fine Structures of an Orthogonal Procaryote Size Copyright The McGrawHill Companies Inc Permission required for reproduction or display Specimen Approximate diameter or width x length Cell Slze Ranges quot quotm Oscillatora Eukaryotes Red blood cell 7000 08 pm hundreds of um E coli 1300 x 4000 BacteriaArchaea gum 750 um Streptococcus 800 1 000 I Viruses Poxvirus 230 x 320 J Influenza virus 85 a 001 quotm 1 quotm T2 Ecoi bacteriophage 65 x 95 uw Tobacco mosaic virus 15 x 300 Pollomyelitis virus 27 Tibl 41 Cell size and volume of prokaryotic cells from the largest to the smalleSt Organism Characteristics Morphology Sizea um Cell volume pm3 E coli volumes Thiomargarita namibiensis Sulfur chemolithotroph Cocci in chains 750 200000000 108 Epulopiscium fishelsoni Chemoorganotroph Rods with 80 x 600 3000000 15 x 106 tapered ends Beggiatoa sp Sulfur chemolithotroph Filaments 50 x 160 1000000 5 X 105 Achromatium oxaliferum Sulfur chemolithotroph Cocci 35 x 95 80000 4 X 104 Lyngbya majuscula Cyanobacterium Filaments 8 x 80 40000 2 x 104 Prochloron sp Prochlorophyte Cocci 30 14000 7 X 103 Thiovulum majus Sulfur chemolithotroph Cocci 18 3000 15 x 103 Staphylothermus marinus Hyperthermophile Cocci in 15 1800 9 x 102 irregular clusters Titanospirillum velox Sulfur chemolithotroph Curved rods 5 x 30 600 3 x 102 Magnetobacterium Magnetotactic Rods 2 X 10 30 15 bavaricum bacterium Escherichia coli Chemoorganotroph Rods 1 x 2 2 1 Pelagibacter ubique Marine Rods 02 x 05 0014 14 x 10 2 chemoorganotroph Mycoplasma pneumoniae Pathogenic bacterium Pleomorphicb 02 0005 25 X 10 3 3Where only one number is given this is the diameter of spherical cells The values given are for the largest cell size observed in each species For example for T namibiensis an average cell is only about 200 um in diameter But on occasion giant cells of 750 um are observed Likewise an average cell of S marinus is about 1 um in diameter bMycoplasma is a cell wallless bacterium and can take on many shapes pleomorphic means quotmany shapesquot Source Data obtained from Schulz HN and BB Jorgensen 2001 Ann Rev Microbiol 55 105 137 Copyright 2009 Pearson Education Inc publishing as Pearson Benjamin Cummings r I pm Surface area 41112 126 umz Volume 1173 42 um3 Surface 3 Volume r 2 um Surface area 503 umz Volume 335 um3 Surface Volume 15 Figure 413 Brock Biology of Microorganisms 1 We 2006 Pearson Prentice Hall Inc Table 31 Plasma membrane Gas vacuole Ribosomes Inclusions Nucleoid Periplasmic space Cell wall Capsules and slime layers Fimbriae and pili 1 Flagella Endospore Cell Organization Copyright The McGrawHill Companies Inc Permission required for reproduction or display Common Bacterial Structures and Their Functions Selectively permeable barrier mechanical boundary of cell nutrient and waste transport location of many metabolic processes respiration photosynthesis detection of environmental cues for chemotaxis An inclusion that provides buoyancy for oating in aquatic environments Protein synthesis Storage of carbon phosphate and other substances Localization of genetic material DNA In typical Gramnegative bacteria contains hydrolytic enzymes and binding proteins for nutrient processing and uptake in typical Gram positive bacteria may be smaller or absent Protection from osmotic stress helps maintain cell shape Resistance to phagocytosis adherence to surfaces Attachment to surfaces bacterial conjugation and transformation twitching and gliding motility Swimming and swarming motility Survival under harsh environmental conditions 10 Copyright The McGrawHill Companies lnc Permission required for reproduction or display Plasma Capsule Ribosomes Cell wall membrane Nucleoid Fimbriae Chromosome Inclusion Flagellum DNA Plasma Membrane 39 encompasses the cytoplasm cytoplasmic membrane 39 selectively permeable barrier interacts with external environment receptors for detection of and response to chemicals in surroundings Transport systems metabolic processes Membrane Structure composed of region phospholipids o q i a 39 n I n o I a u llpld bllayer HydrophiliCE t r I 1 l P I 1 t t 3quotquot t r39 quot1 1 lt x t x y l v 1 r 39n r 39 i 39 v r39 lt39 39gt quot vquot r Mquot m 13 IJ I A1quot f H my I l 5 l t 39139 a y A lll I 1 L 1 t K it klquot g 3 cquot r g H r R w u 5 J V A a W t a J M I 39 39 I 39 g Fatty aCIdS Hydrophobic 39 amphlpathlc llpldS region x 31 quotquott oo O hydrophlllc region ff 9 9 if f f nonpolar tails Glycem39 Phosphate Figure 414 Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc a I 2 5 4 quotV I H 7 quotg y 1 V J w 397 fr 39 39 I I v gt I 39t l 393 quot I L 1 39 K I I Wquot m v w lt nix7qu st trim Hrquot 35 gt1 r39 quot5quotl H5 quot1 quot1391 LIP 1M 44quot t39i i H i39 39 Iquot1wr 4 M y I w 39 1 39 12 Bacterial Lipids Copyright The McGrawHill Companies incl Permission required for reproduction or di ssss y o saturatlon levels of 5H2 membrane llplds 0 z re ect environmental Glycerol conditions 5 52 bacterial membranes organza I 2 I 2 fattyacid chains lack sterols but do contain sterollike molecules hopanoids low stabilize membrane 2342 Suppose you have discovered a microorganism that is 7 um in diameter Which one of the following hypotheses would be the best to propose a the microbe is a Virus b The microbe is a bacterium c The microbe is a eukaryote d The microbe is a Virus 21 bacterium 15 Fluid Mosaic Model Copyright The McGrawHill Companies Inc Permission required for reproduction or display Oli osaccharide we Glycollpld g Integral 4 protein Integral I protein Hydrophobic Hopanoid q WRWI I I 39 a r I i 39 I V y 1 K C r Pri hrali protein i 16 Membrane Proteins peripheral loosely connected to membrane comprise 2030 of the membrane proteins integral embedded within membrane amphipathic comprise 7 080 of the membrane proteins carry out important functions transport secretion Energy conservation Bacterial Cell Wall Rigid structure that lies just outside the plasma membrane Copyright The McGrawHill Companies Inc Permission required for reproduction or display quotv win Pump 11 3 in 1 contains peptidoglycan i p Only found in Domain 5 u 39 39 39 Bacteria Very protective and selective to What can come into the cell Items smaller than 2 um functions provides shape to cell protects from osmotic lysis may contribute to pathogenicity Courtesy of MR J Salton NYU Medical Center protects from toxic substances Cell Walls of Bacteria Bacteria are divided into two major groups based on the Gram stain differential staining due to cell wall structure Copyright The McGrawHill Companies Inc Permission required for reproduction or display The gramnegative cell wall Copyright The McGrawHill Companies Inc Permission required for reproduction or display The grampositive cell wall Cell P td I ep l 09 ycan wall Plasma membrane l i Outer membrane Peptidoglycan Plasma membrane k XCell wall Periplasmic Beven dgeJBiolo ica hoto ervice TJ BeveridgelBiological Photo Service 18 purple Name That Wall Outer membrane g g L Cytoplasmic Peptidoglycan membrane Cytoplasmic membrane T D Brock and S F Conti Figure 427d Brock Biology of Microorganisms 1 1 le 2006 Pearson Prentice Hall Inc Figure 427c Brock Biology of Microorganisms 1 We 2006 Pearson Prentice Hall Inc Grampositive gramnegatwe 19 Peptidoglycan Structure important component of both gram positive and gramnegative bacteria Even though it s thin in gramnegative it helps to protect the cell and give it shapestructure meshlike polymer two alternating sugars form backbone N acetylglucosamine gNAG N acetylmuramic acid NAM 20 alternating D and L amino acids CHZOH CHZOH NAcetyl QVOUP CH3 i0 Lysozyme NH 39 sensitive P t39d quot I b d ep 39 e I H3C CHC I on crosslinks 39r r 5 39 39 39 39 39 quot NHI lAlunme I s CCHzclquotz CH CP B 39 742 quot 39TH 3 nGluiumic acid Itquot39 I s 310 C c 9392 552 9quot2 CE C I Mesodmmmo x H I lHI pimelic acid I i 3935 Cquot39 5005 s K nAlunlne F Figure 429 Brock Biology of Microorganisms 11e 21 c 2006 Pearson Prentice Hall Inc Peptidoglycan chains are crosslinked by mtides for strength ri t T e McGrawHill Compa 39 ct on or display E 60 direct linkage S aureus indirect linkage A 1 3 7 39 V j v 3 gag4 W If v j i i G y N I h x b a Pepti39d e interbridge 22 Copyright The McGrawHill Companies Inc Permission reQUired for reproduction or display I NAM Peptide Qdechmn NAG PoWsacoha de backbone 23 Figure 30c Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc GramPositive Cell Walls composed primarily of peptidoglycan up to 90 of wall may also contain large amounts of teichoic acids negatively charged maintain structure of cell envelope protect from harmful substances may bind to host cells 24 pathogenic bacteria lipoteichoic acids attached to membrane some grampositive bacteria have a layer of proteins on surface of peptidoglycan Grampositive Peptidoglycan 39 Membrane 25 Copyright The McGrawHill Companies Inc Permission required for reproduction or display Teichoic acid r Lipoteichoic acid Peptidoglycan l Periplasmic e space gt Plasma membrane 1 26 GramNegative Cell Walls consist of a m layer of peptidoglycan surrounded by an outer membrane outer membrane composed of lipids lipoproteins and popolysaccharide LPS m teichoic acids Gramnegative 3 e Peptidoglycan It i L Membrane i Periplasm Outer membrane lipopolysaccharide and protein Figure 27b Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc GramNegative Cell Walls peptidoglycan up to Outer membrane lies 10 of cell wall outside the thin Periplasm may Peptidoglycan layer constitute 20 40 Braun s lipoproteins of cell volume connect outer many enzymes membrane to present in periplasm peptidoglycan hydrolytic enzymes to break down food transport proteins and other proteins 27 28 Copyright The McGrawHill Companies Inc Permission required for reproduction or display OSpelf C sidelphains fl ll l 39Popolysacchande l U will ll if Outer membrane Periplasmic space and peptidoglycan Plasma membrane Phosphollpid Peptidoglycan Integral protein Lipopolysaccharide LPS three parts lipid A Extremely important core polysaccharide 0 side chain 0 antigen because it will be recognized as foreign in the body 0 specific polysaccharide Lipid A embedded in outer membrane core polysaccharide amp 0 side chain extend out from the cell Ospeci c polysaccharide Core polysaccharide Lipid A I II ll r 4 0 IOI Copyright 2009 Pearson Education Inc publishing as Pearson Benjamin Cummings 29 Copyright The McGrawHill Companies Inc Permission required for reproduction or display H lYlan Abe Tha Gal n Man Abe Rha Gal a l Glc NAG I Gal I IC 6339 Core polysaccharide Hep 0 side chain I Hep eihanolamine I KDO l39 I 5 KDO KDO ethanolamine J 1y H V t 4 Fatty acid Lipid A g 9 A 39 Y a 5 54 we a b From M Kastowsky T Gutberlet and H Bradaczek Journal of Bacteriology 7744798 4806 1992 30 31 Importance of LPS contributes to negative charge on cell surface core polysaccharide helps stabilize outer membrane structure lipid A may contribute to attachment to surfaces and biofilm formation Biofilm assemblage of bacteria that makes a matrix that helps them stick together creates a permeability barrier may mutate to protect from host defenses 0 antigen can act as an endotoXin poison lipid A Causes gastrointestinal distress vomitdiarrhea 32 GramNegative Outer Membrane Permeability more permeable than plasma membrane due to presence of porin proteins and transporter proteins porin proteins form channels through which small hydrophilic molecules like sugars can pass 4r V I I 39 x n 1 39 39 39 i v er 39 K quot h s x 39 1 39 o o 1 I l 39 I l I u o l I I a I amp I qquot gt39 f 1 Georg E Schulz Comparison of GramPositive and GramNegative Cell Walls Lipoteichoic acid Teichoic acid ll l lipoprotein Ospecific sude chains as O gt 8H y Lipopolysaccharide 8 4391 0 7 Outer membrane lt f 1r e Periplasmic a v 5 space f Periplasmic gtspace and peptidoglycan Plasma membrane Plasma membrane Phospholipid Peptidoglycan Integral protein 33 Question of the day If you only had access to the cell wall of a bacterium how would you determine if it was gram or gram 39 B look for the presence or absence of teichoic acids 39 C Look for the presence or absence of lipopolysaccharides Osmotic Protection Hypotonic environments SOIUte outside cell lt SOIUte inside cell water moves into cell and cell swells cell wall protects from lysis Lysislysing breaking open Hypertonic environments SOIUteoutside cell gt SOIUteinside cell water leaves the cell Plasmolysis occurs Cell shrinks as water leaves 35 36 Evidence of Protective Nature of the Cell Wall Lysozyme breaks the bond between NAG and NAM Penicillin inhibits peptidoglycan synthesis if cells are treated with either of the above they will wit they are in a hypotonic solution This picture demonstrates a cell lysing during cell division Without A Cell Wall survival in isotonic environments protoplasts spheroplasts Mycoplasma no cell wall plasma membrane more resistant to osmotic pressure Copyright the McGrawHill Companies Inc Permission required for reproduction or display Penicillin inhibition of wall synthesis Incubation in isotonic Riftng Swelling due If a 39 r f 39 quot 39 L sis medium V medlum I to H2O Influx y 1 gt gt gt gt1 Protoplast 37 H20 Components Outside of the Cell Wall Capsules Slime Layers 39 usually CODIPOSed 0f similar to capsules except polysaccharides sugar well organized and not easily removed from cell easily removed protective advantages resistant to phagocytosis protect from desiccation drying out especially in a hypertonic environment They also eat from Within their capsule if needed to survive exclude viruses and detergents diffuse unorganized and slime may aid in motility 38 END OF UNIT 1 The Cytoskeleton role in cell division protein localization and determination of cell shape Copyright The McGrawHill Companies Inc Permission required for reproduction or display Table 32 Bacterial Cytoskeletal Proteins Type Function l Tubulin Homologues FtsZ Cell division BtubABtubB Unknown TubZ Possibly plasmid segregation Actin Homologues MamK Positioning magnetosomes MreBMbl Helps determine cell shape may be involved in chromosome segregation localizes proteins ParM Plasmid segregation Intermediate Filament Homologues CreS crescentin Induces curvature in curved rods Unique Bacterial C ytoskeletal Proteins MinD Prevents polymerization of FtsZ at cell poles 40 ParA Segregates chromosomes and plasmids Comments Widely observed in bacteria and archaea Observed only in Prosthecobacter spp thought to be encoded by eukaryotic tubulin genes obtained by horizontal gene transfer Encoded by large plasmids observed in members of the genus Bacillus Observed in magnetotactic species Most rodshaped bacteria Plasmid encoded Caulobacter crescen tus Many rodshaped bacteria Observed in many species including Vibrio cholerae C crescentus and Thermus thermophilus 41 Inclusions aggregates of organic or inorganic materia granules Copyright The McGrawHill Companies Inc Permission required for reproduction or display crystals globules some are enclosed by a single layere membrane or invaginations of plasma membrane Ralph A SlepeckyNisuals Unlimited Storage Inclusions Copyright 0 The McGtawHil Companles Inc Permission required for reproductlon or display storage of nutrients 7 metabollc end a 3 at 8 products energy o quot building blocks y x w Carbon K39q glycogen a a L poly hydroxybutyrate 9 1 PHB g 9 S I Phosphate av polyphosphate m OJ Sulfur globules r 39 39 39 Jag periplasm 9 Reprinted from Th e Shorter Bergey39s Manual 0 Determinauve Bade ology 80 John 6 Hon Editor 1977 O Bergey s Manual Tmst o Publishedby Mlllams a WIldns Baltimore MD 42 cyanophycm granules Other Inclusions gas vacuoles magnetosomes provide buoyancy magnetite particles for orientation in Earth s magnetic field Copyright The McGrawHill Companies Inc Permission required for reproduction or display v s Copyright 6 The McGraw Hill Companles Inc Perrntssmn required lor reproduction or display Periplasfnjc space r Outer membrane Magnetosome Plasma membrane b Reprinted from Biophysical Joumal Vol 86 Marina Belenky Rebecca Meyers and Judith Herzfeld Subunit Structure of Gas Vesicles Answer MALDlTOF Mass Spectrometry Study January 2004 with permission from Elsevier 43 a Y Gorby Chapter 37 39 Bacterial Cell Structure and Function External Structures 39 extend beyond the cell envelope in bacteria and archaea functions protection Attachment to surfaces horizontal gene transfer cell movement fimbriae pili and flagella Fimbriae and Pili need microscope to see fimbriae and pili short thin hairlike proteinaceous appendages up to 1000cell narrow 5 nm in diameter mediate attachment to surfaces some type IV pili required for motility twitching or DNA uptake seX pili similar to fimbriae except longer thicker and less numerous 110cell genes for formation found on plasmids fertility plasmids required for conjugation 2006 Pearson Prentice Hall Inc 0 Figure 437 Brock Biology of Microorganisms 1 1e Os o s 39 t I ViruscoVered A pilus v Figure 438 Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc J T i J P Duguid and F Wilkinson I Charles C Brinton Jr Flagella Threadlike appendages extending outward from plasma membrane and cell wall functions motility and swarming behavior attachment to surfaces may be Virulence factors Make them better pathogens Patterns of Flagella Distribution 39 O monotrichous one agellum polar agellum agellum at w of cell amphitrichous one agellum at each end of cell lophotrichous cluster of agella at one or both ends peritrichous spread over entire surface of cell Copyright The McGrawHill Companies Inc Permission required for reproduction or display Copyright The McGrame Companies In Permission required for reproduction or display 39 A 39 a Pseudomonas monotrichous 39 polar flagenation b SpiriIum lophotrichous flagellation ECS ChanMsuals Unlimited ECS ChanNisuals Unlimited Copyright The McGraw Hill Companies Inc Permission required for reproduction or display c P vulgaris peritrichous flagellation George J A lderNisuals Unlimited Flagellar Structure Filament rigid and 20 nm in diameter Hook hollow basal body motor Filament Flagellin Hook Outer membrane Periplasm Peptidoglycan 39 Basal body If Ag Ri I 366 Cytoplasmic membrane Mot protein Fli proteins Mot protein motor switch I l 45 nm Figure 456a Brock Biology of Microorganisms 1 1e 2006 Pearson Prentice Hall Inc Copyright The McGrawHill Companies Inc Permission required for reproduction or display Filament Hook Outer membrane Peptidoglycan layer u n a u f I n IICll 39I II J L 7 w Periplasmic space I Inltoco39 a a n a n o a 4 u u a n n a 39 39 39 Plasma quotquot quot membrane u a n 1 a u n p o u b Copyright The McGraw Hill Companies lnc Permission required for reproduction or display I LPS 0 up Flagellin do a a 39 Filament 391 39I cap protein Outer 39 membrane Peptidoglycan 4 Plasma 39 membrane mRNA Ribosome 1O Mechanism of Flagellar agellum is 2 part motor that produces torque rotor C ring and MS ring turn and interact with stator stator Mot A and Mot B proteins Movement Copyri hhhhhhhhhhhhhh Hi IIIIIII nies Inc Permissi ooooo ui rrrrrrrrrrrrrr ti oooo display Filament MotA and MotB create a channel through which protons can flow This causes the flagellum to rotate a r u x v y t r c u r u u 1 Outer membrane r r v v r r 1 I39l O C C C O O 39 39 39 39 39 1 Peptidoglycan layer JPeriplasmic space MS ring IA39A A K O C O O O U C C C O 0 Plasma membrane a Copyright ttttttt awHi IIIIIII nies Inc Permissi oooooo ii rrrrrrrrrrrrrr ti oooo display agellum rotates like a propeller up to 1100 revsec in general counterclockwise CCW rotation causes forward motion m in general clockwise rotation CW disrupts run causing cell to stop and tumble 11 W a W J Forward run b A ff Forwa d 9 c d Peritrichous Flagellar Movement Tumble g flagella ushed Bundled K p apart flagella CW rotation CCW rotation 5 Fla llb dld ge a un e 6 CCW rotation Peritrichous Figure 458a k I f g nisms 11e entice Hall Inc 12 Spirochete Motility G multiple agella form axial fibril which Winds around the cell agella remain in periplasmic space inside outer sheath corkscrew shape exhibits exing and spinning movements AF axial fibril AF PC 08 PC protoplasmic cylinder IP 08 outer sheath IP insertion pore 13 Twitching and Gliding Motility may involve Type IV pili andor slime twitching pili at ends of cell short intermittent jerky motions cells are in contact with each other and surface gliding Copyri hhhhhhhhhhh awHi IIIIIII nies Inc Permissi ooooo ui rrrrrrrrrrrrrr ti oooo display Copyright The McGrawHill Companies Inc Permission required for reproduction or di ssss y Cell movement I I I quot Polysaccharlde I I 39 Rotation W l I I I 4 Motors maintain fixed positions with respect to the substratum and push the cell body forward b a Produces slime 14 Little feet and slime Chemotaxis 39 movement toward a chemical attractants most often foodnutrients or away from a chemical repellent 39 concentrations of chemoattractants and chemorepellants detected by chemoreceptors on surfaces of cells complex but rapid responses occur in less than milliseconds 15 2 to over 60 cell lengthssec 16 PositiveNegative Chemotaxis Toward caused by loweringthe frequency of tumbles Runs in direction of attractant are longer biased random walk Away involves similar but opposite responses AHrndnnI present Figure 461 b Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc 17 The Bacterial Endospore complex dormant structure formed by some bacteria various locations within the cell resistant to numerous environmental conditions heat Radiation chemicals Desiccation drying nnf Copyright The McGrawHill Companies Inc Permission required for reproduction or display lt 5 Central Subterminal Swollen sporangium Terminal Endospore Structure Exosporium Cortex spore coat core Copyright The McGraw Hill Companies Inc Permission required for reproduction or display Exosporium Core Coat Inner membrane Outer membrane Germ cell wall Cortex a b CNRlPhoto Researchers Inc 18 19 What Makes an Endospore so Resistant 39 COI E low water content calcium dipicolinate CaDPA Stabilizes DNA to help Withstand environment SASPs small acidsoluble DNAbinding proteins slightly lower exosporium and spore coat Table 43 Differences between endospores and vegetative cells Characteristic Vegetative cell Endospore Structure Typical grampositive Thick spore cortex Spore coat cell a few gramnegative exosporium cells Microscopic appearance Nonrefractile Refractile Calcium content Low High Dipicolinic acid Absent Present Enzymatic activity High Low Metabolism 02 uptake High Low or absent Macromolecular synthesis Present Absent mRNA Present Low or absent DNA and ribosomes Present Present Heat resistance Low High Radiations resistance Low High Resistance to chemicals for Low High example H202 and acids Stainability by dyes Stainable Stainable only with special methods Action of lysozyme Sensitive Resistant Water content High 80 90 Low 10 25 in core Small acidsoluble proteins Absent Present product of ssp genes Cytoplasmic pH About pH 7 About pH 55 60 in core 20 Copyright 2009 Pearson Education Inc publishing as Pearson Benjamin Cummings 21 Sporulation and Germination Devemsme 9 J Hans Hippe Germination Hans Hippe Sporulation Cell wall Cytoplasmic membrane DNA g 39 Phys V A E l a 39 a more dense Developing endospore a 39 rs Stage III around protoplast omequot formation Figure 451 Brock Biology of Microorganisms le 22 2006 Pearson Prentice Hall Inc core Stage IV 1 Inner spore membrane Stage VII Exosporium Free 1 Armquot 39 Core 5 re release 39f39fr39ee endospore resistance to heat and chemicals pro lhction of SKSPs and dipicolinic acid coat layers are formed 39 f A f 39 i Exosporium rziquaI cor rfs Primordia39 formed between the two cortex membranes Formation of Vegetative Cell activation prepares spores for germination often results from treatments like heating germination environmental nutrients are detected spore swelling and rupture of spore coat loss of resistance increased metabolic activity outgrowth emergence of vegetative cell 23 Chapter 71 73 74 76 77 Microbial Growth and Reproduction Growth of Microorganisms Growth often referring to an increase in the number of cells microbiologists usually study population growth rather than growth of individual cells 39 Binary FiSSiOH two cells arise from one cell elongation 0 cellular constituents increase proportionally Genome chromosome of the cell is replicated and segregated cell division septum formed at midcell increase in cell number One cell 9 Two cells one generation Some generation times can be as little as 20 minutes Copyright The McGrawHill Companies Inc Permission required for reproduction or display Cell wall Cell membrane 0 Chromosome 1 O Chromosome 2 0 Ribosomes a A young cell at early phase of cycle b A parent cell prepares for division by enlarging its cell wall cell membrane and overall volume c The septum begins to grow inward as the chromosomes move toward opposite ends of the cell Other cytoplasmic components are distributed to the two developing cells d The septum is synthesized completely through the cell center and the cell membrane patches itself so that there are two separate cell chambers e At this point the daughter cells are divided Some species separate completely as shown here while others remain attached forming chains doublets or other cellular arrangements Copyright McGrawHill Companies Inc Permission required for reproduction or display Why do bacteria make fermentation products during the process of fermentation To provide nutrients for growth For anaerobic ATP production To oxidize NADH All of the above N 0 reason they are waste products The Growth Curve observed when microorganisms are cultivated in batch culture culture incubated in a closed vessel with a single batch of medium usually plotted as logarithm of cell number versus time has four distinct phases lag exponential stationary and death Log number of viable cells gt Copyright The MoGraw Hill Companies Inc Permission required for reproduction or display Stationary phase Exponen alaog phase Death phase Time gt Lag Phase 39 cell synthesizing new components to replenish spent materials to adapt to new medium or other conditions varies in length in some cases can be very long very short or even absent Exponen alPhase also called log phase rate of growth is constant rate of growth is maximal population is most uniform in terms of chemical and physical properties during this phase Cells are healthiest at midexponential phase You would want to inoculate during this time frame Stationary Phase total number of viable cells remains constant metabolically active cells stop reproducing OR reproductive rate is balanced by death rate so no net increase in number possible reasons for this phase nutrient limitation limited oxygen availability toxic waste accumulation critical population 109bacteriaml density reached 1O Starvation Responses Morphological changes endospore formation decrease in size production of starvation proteins increase crosslinking in cell wall Dps protein protects DNA chaperone proteins prevent protein damage Some enzymes can fix the denatured DNA Persister cells longterm survival Can last years Pathogens that go into this phase can become more virulent increased virulence 11 Death Phase 39 tOtal number Of Viable those that can reproduce C6118 is decreasing removal of critical nutrients below a threshold level metabolic endproduct reaches toxic level death irreversible loss of ability to reproduce Lysis may or may not occur Cannot be resurrected after lysed Log number of viable cells gt Exponen alaog phase Lag phase no increase Stationary phase population growth ceases maximal rate of division and population growth Death phase decline in population size Time gt The Mathematics of Growth Copyright The McGrawHill Companies Inc Permission required for reproduction or display Generation time or doubling time 60 time required for the 50 A population to double in A 1 39000 size 40 Smaller cells grow faster 3 varies depending on g 30 0 O o spec1es and enV1ronmental 0500 g conditions g 20 E exponential growth 539 lt55 3 cell number doubles 10 Within a fixed time period 0 I l I 0000 0 20 40 00 80 Minutes of incubation 13 14 Copyright The McGraw Hill Companies Inc Permission required for reproduction or display Table 78 An Example of Exponential Growth L Division Population2 Time1 Number 2quot No x 2 IogmNt 0 0 20 1 1 0000 20 1 21 2 2 0301 40 2 22 4 4 0602 60 3 23 8 8 0903 80 4 24 16 16 1204 1 The hypothetical culture begins with one cell having a 20minute generation time 2 Number of cells in the culture Time h 0 05 1 1 5 2 25 3 35 Total number Time Total number of cells h of cells 1 4 256 28 2 45 512 29 4 5 1024 21 8 55 2048 21 1 16 6 4096 2 32 64 128 10 1048576 219 Figure 66a Brock Biology of Microorganisms 1 We 2006 Pearson Prentice Hall Inc 15 Calculating Generation Time 1 Nt NO X 2 39 Nt is the nal population at time t 39 N0 is the initial population number 39 n number of generations for t 2 log Nt log N0 n log 2 note log 2 0301 3 n log N log N9 0301 4 16 Generation Time g n 33 log Nt log N N 10 X 108 N0 50 X 107 1 n 338 77 2 n 1 generation during t 3 t 2 4 g tn g 2 h generati0n 1x108 gt 7 t2 Population 8X10 quot1 doublesi t 2h 6x107 9 3 2h 4x107 E x 7 3x107 U 2x107 2h 1x107 0 1 2 3 4 5 Slope 015 Time h Figure 67b Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc Copyright The McGrawHill Companies Inc Permission required for reproduction or display Table 79 Examples of Generation Times1 I Incubation Temperature Generation 1 Microorganism C Time Hours V Bacteria 39 Escherichia coli 40 035 Bacillus subtilis 40 043 l Staphylococcus aureus 37 047 i Pseudomonas aeruginosa 37 058 1 I Clostridium botulinum 37 058 I Mycobacterium tuberculosis 37 z 2 l Treponema pallidum 37 33 l Protists l Tetrahymena geleii 24 2242 Chlorella pyrenoidosa 25 775 I l Paramecium caudatum 26 104 l Euglena gracilis 25 109 1 Giardia lamblia 37 l 8 Ceratium tripos 20 828 Fungi l Saccharomyces cerevisiae 30 2 Monilinia fructicola 25 30 L k 1 22015 which of the following statements accurately describes the exponential growth phase of a bacterial population 18 grown in a batch culture The rate of bacterial growth is constant exponential The reproductive rate is balanced by the death rate stationary The total number of Viable cells remains constant stationary The rate of bacterial growth is gradually increasing as the bacteria adapt to environmental conditions lag Measurement of Cell Numbers Direct Total cell counts count the number of cells that are observed in the medium Counting chamber Electronic counter Viable cell counts count the number of CFUs that are culturable from the medium Plating techniques Membrane filter Indirect Dry weight to try to determine the amount of cells could be weighing the amount of DNA Could lose a lot though No way to distinguish what s alive and dead 19 Turbidity Total Cell Count PetroffHausser Counting Chamber To calculate number per milliliter of sample 12 cells x 25 large squares x50x 103 15x 107 b I I I I I i I l Number mm2 N b I 3 I Sample added here care must Microscopic observation all um er mm J be taken not to allow overflow cells are counted in large square N b 3 I space between coverslip and 12 cells in practice several um er cm m slide is 002 mm 5 mm Whole squares are counted and grid has 25 large squares a total the numbers averaged area of 1 mm2 and a total volume of 002 mm3 Figure 69 Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc 20 Plating Methods 3939 fi iigta 139 39 39 be counted plate dilutions of population k ilution o o I 1 ml 1 ml 1 ml 1 ml on sultable solld medlum 139 i M V E F if V I a q count number of colonles 9ml 1 l ll r i broth 1 calculate number of cells in 110 1100 1 03 1104 1105 1106 10 10 2 103 10 105 106 orlglnal populatlon Plate 1ml samples o ux a r r 4 s2 3 f I 0 o o u u 1 o I 0 39 I I o quot a O 39 o D gtI Population size expressed as I h 139 i b T00 many colonies colonies colonies colonies colony formlng unlts colonies l tocount 159 x 103 159 x 105 Plate Dilution Cells colonyforming count factor units per milliliter of original sample Figure 611 Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc Spreadplate method Surface colonies Incubation Sample is pipetted Sample is spread evenly over Typical spreadplate onto surface of agar surface of agar using sterile results plate 01 ml or less glass spreader Pourplat method 2 Sample is pipetted Sterile medium is added and Typical pourplate into sterile plate mixed well with inoculum results Figure 610 Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc Subsurface Surface colonies colonies Incubation Membrane filter removed and placed in plate Water sample Membrane filtered through containing the 39ter 0 a membrane filter quot39Z39 appropriate quotquot Incubation rquotquot quot l g gt a colonies Turbidity Measurements Filter or l39ght39 0 prism 540 nm Figure 612a Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc Incident K llllll z 2 I Unscatter quot light I Sample Photocell measures Recorder containing unscattered light I cells 0 umts Spectrophotometer Klett photometer PticaI dens OD Klett units OD lo 0002 Log l More cells 9 more absorbed scattered light less transmitted unscattered light detected 24 The Influence of Environmental Factors on Growth Microbes must be able to respond to changing environmental conditions environmental factors that affect growth Water availability pH Temperature oxygen pressure radiation extremophiles microbes that grow under harsh or extreme environmental conditions 25 Table 72 Microbial Responses to Environmental Factors Descriptive Term De nition Solute and Water Activity Osmotolerant Halophile pH Acidophile Neutrophile j Alkaliphile Temperature Psychrophile Psych rotroph Mesophile Thermophile Hyperthermophile Able to grow over wide ranges of water activity or osmotic concentration Requires high levels of sodium chloride usually above about 02 M to grow Growth optimum between pH 0 and 55 Growth optimum between pH 55 and 80 Growth optimum between pH 80 and 115 Grows at 0 C and has an optimum growth temperature of 15 C or lower Can grow at 0 7 C has an optimum between 20 and 30 C and a maximum around 35 C Has growth optimum between 20 and 45 C Can grow at 55 C or higher optimum often between 55 and 65 C Has an optimum between 85 and about 113 C Oxygen Concentration Obligate aerobe Facultative anaerobe Aerotolerant anaerobe Obligate anaerobe Microaerophile Pressure Piezophile barophile L Completely dependent on atmospheric 02 for growth Does not require 02 for growth but grows better in its presence Grows equally well in presence or absence of 02 Does not tolerate 02 and dies in its presence Requires 0 levels between 2 10 for growth and is damaged by atmospheric 0 levels 20 Growth more rapid at high hydrostatic pressures Copyright The McGraw Hill Companies Inc Permission required for reproduction or display Representative Microorganisms Staphylococcus aureus Saccharomyces rouxii Halobacterium Dunaiella Ectothiorhodospira Sulfolobus Picrophilus Ferroplasma Acon tium Escherichia Euglena Paramecium Bacillus alcalophilus Natronobacterium Bacillus psychrophilus Chlamydomonas nivalis Listeria monocytogenes Pseudomonas uorescens Escherichia coli Trichomonas vaginalis Geobacillus stearothermophilus Thermus aquaticus Cyanidium cadarium Chaetomium thermophile Sulfolobus Pyrococcus Pyrodictium Micrococcus Iuteus most protists and fungi Escherichia En terococcus Saccharomyces cerevisiae Streptococcus pyogenes Clostridium Bacteroides Methanobacterium Campyobacter Spirillum volutans Treponema pallidum Photobacterium profundum Shewanella benthica Solutes and Water Activity Water activity aw amount of water available to organisms aW values range from 0 to 1 water associated with solutes is unavailable to microorganisms higher solute lower aW adaptations hypotonic solutions use mechanosensitive MS channels in membrane to allow solutes to leave less water comes into cell Solutes leave so that the concentration gradient isn t as large so water doesn t come into the cell hypertonic solutions increase internal solute concentration with compatiblesolutes 9 more water comes into cell Water will leave in a hypertonic solution Allows solutes in so that water can come 1n 26 Table 62 Water activity of several substances Water activity aw Material Example organisms 1000 Pure water Caulobacter Spirillum 0995 Human blood Streptococcus Escherichia 0980 Seawater Pseudomonas Vibrio 0950 Bread Most grampositive rods 0900 Maple syrup ham Grampositive cocci such as Staphylococcus 0850 Salami Saccharomyces rouxii yeast 0800 Fruit cake jams Saccharomyces bailii Penicillium fungus 0750 Salt lakes salted fish Halobacterz39um Halococcus 0700 Cereals candy Xeromyces bisporus and dried fruit other xerophilic fungi Selected examples of prokaryotes or fungi capable of growth in culture media adjusted to the stated water activity Table 62 Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc Effects of NaCl on Microbial Nonhalophile does not require NaCl can grow if lt 1 NaCl 0 Example E coli Halotolerant bridges between non and halophile Halophile requires NaCl for growth grow optimally at gt02 M 1 15 NaCl example skin extreme halophiles require 2 62 M 15 30 NaCl examples found in salt fish around salt turiiquot sP Growth Growth rate 0 4 llonhuloplule Example Escherichia coli W Extreme Example Example huloplnle Staphylococcus Vibriofischeri Example aureus Halobacterium salinarum 0 Figure 623 Brock Biology of Microorgani earson Prentice Hall Inc 28 reason for pinkred appearance of Dead sea NaCl sms 11le Copyright The McGrawHill Companies Inc Permission required for reproduction or display H pH pH optima of some microbes ACIDIC Ferropasma A measure of the relative acidity of a solution DunaieIa acidophila E Cyanidium cadarium E Lemonlu39ce Thiobacilus thiooxidans B AC39d mlne dramage Sufoobus acidocaldarius A Human stomach fluid Grapefruit juice Oranges Beer Tomato juice Physarum polyciphalum E negative loganthm of the jf E 3f 2 35 2 i038a 10 7M NEUTRAL 7 Pure water hV O 2 l Human blood Staphylococcus aureas B v Seawater Nitrosomonas spp B concentratlon 7 Soap Microcystis aeruginosa B Bacillus alcaophilus B Household ammonia Bleach 29 ALKALINE Question 22315 Which one of the following methods would be appropriate to use for determining the number of viable cells in a bacterial culture a Direct microscopic count using a Petroff Hausser Counting Chamber i Could be counting dead ones but there are new machines that can leave out dead ones from count b Cell mass measurement dry weight c Turbidometric measurement a Overestimate 1 Plate count a Might get underestimate e None of the above 31 pH Acidophiles growth optimum between pH 0 and pH 55 neutrophiles growth optimum between pH 55 and pH 7 Alkaliphiles alkalophiles growth optimum between pH 85 and pH 115 Response to pH most microbes maintain an internal pH near neutrality Acid shock proteins Prevent denaturation many microbes change the pH of their habitat by producing acidic or basic waste products Temperature microbes cannot 32 regulate internal temperature exhibit distinct cardinal growth temperatures minimum maximum optimum Enzymatic reactions occurring at maximal Enzymatic reactions occurring at increasingly possible rate gt0ptimum f rapid rates 3 o L U Minimum Maximum Temperature Membrane gelling transport processes so slow that growth cannot occur Protein denaturation collapse of the cytoplasmic membranethermal Iysis Figure 616 Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc Temperature Classes of Microbes Example ll erlhermohile p e thermo ile Bacillus stearothermophilus Example Example A Thermococcus celer Pyrolobus fumam Example 60 Escherichia coli 88 1 06 Example Polaromonas vacuolat Growth rate 0 1039 20 30 40 50 60 70 80 90 100 110 120 Temperature Figure 617 Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc 33 34 Typical Growth Temperature Ranges psychrophiles 9 lt O 200 C optimum lt 15 C ice psychrotroph 9 O 350 C optimum 2030 C mesophiles 9 15 450 C optimum 2045 C roombody temperature thermophiles 9 45 850 C optimum 5565 C Hyperthermophiles e 65 1130 C optimum 65113 C 35 Oxygen and Bacterial Growth aerobe grows in presence of atmospheric oxygen which is z 20 O2 Obligate strict aerobe requires 2 for growth and will die without it anaerobe grows in the absence of O2 obligate strict anarobe usually killed in presence of O2 microaerophile requires 2 10 2 Facultative aerobeanaerobe does not require 2 but grows better in its presence aerotolerant anaerobe grows with or without 02 Table 64 Oxygen relationships at microorganisms Group Relationship to 02 WW Habitat Aerobes Obligate Required Aerobic respiration Micrococcus luteus B Skin dust Facultative Not required but growth Aerobic respiration anaerobic Escherichia coli B Mammalian large better with 02 respiration fermentation intestine Microaerophilic Required but at levels Aerobic respiration Spirillum volutmrs B Lake water lower than atmospheric Anaerobes Aerotolerant Not required and growth Fermentation Streptococcus pyogenes B Upper respiratory tract no better when 02 present Obligate Harmful or lethal Fermentation or anaerobic Methanobacterimn A Sewage sludge digestors respiration formicicmn anoxic lake sediments quot Letters in parentheses indicate phylogenetic status B Bacteria A Archaca Representatives of either domain of prokaryotes are known in each category Most eukaryotes are obligate aerobes but facultative aerobes for example yeast and obligate anaerobes for example certain protozoa and fungi are known 1 Listed are typical habitats of the example organism Table 64 Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc 36 Oxygen and Bacterial Growth f39 I Oxic zone Anoxic zone 37 38 Oxygen Sensitivity oxygen easily reduced to toxic reactive oxygen species ROS superoxide radical Hydrogen peroxide hydroxyl radical Aerobes produce Copyright The McGrawHill Companies Inc Permission required for reproduction or display Lid Lockscrew Clamp M22H20 Catalyst chamber Contains palladium pellets H2 Rubber gasket seal Oxygen removed from chamber by combining with hydrogen to form water This reaction is catalyzed by the palladium pellets Anaerobic indicator strip 7 Methylene blue becomes colorless in 39i absence of 02 protective enzymes superoxide dismutase SOD Catalase peroxidase Water is added to chemicals in envelope to generate H2 and C02 Carbon dioxide promotes more rapid growth of microorganisms Gas generator envelope 02 equot gt 02quot Superoxide 02 e 2 H gt H202 Hydrogen peroxide H202 e H gt H20 OH Hydroxyl radical OH e39 H gt H20 Waler Overall 02 4e 4 H gt2 H20 Figure 627 Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc a Cutulnse H202 H202 2 H20 02 b Peroxidase H202 H gt 2 H20 NAD c Superoxide dismuiuse 02 02 2 HH202 02 d Superoxide dismutosecoioluse in combination 40239 4 H gt2 H20 3 02 e Superoxide reduduse 02 2 W Cyt creduced 39 quot202 Cyt Coxidized Figure 628 Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc Question 22515 The ocean has an average of pH of 83 an average salt concentration of 3 and an average temperature of 5 degrees Celsius If a bacterium lives in these average conditions of the ocean it could be described as an A Acidophile extreme halophile psychrotroph B Extreme alkaliphile halotolerant thermophile C Alkaliphile halophile psychrophile D N eutrophile extreme halophile mesophile E Extreme acidophile nonhalophile 41 hyperthermophile Microbial Growth in Natural Environments microbial environments 42 are complex constantly changing often contain low nutrient concentrations oligotrophic environment microbial growth depends on Nutrient supply and water supply tolerance of environment and its changes inhibitory substances tolerate products of growth and toxins most microbes grow attached to surfaces as biofilms in mass communities slim In moist conditions Biofilm Formation microbes reversibly attach to conditioned surface and release polysaccharides proteins and DNA to form the extracellular polymeric substance EPS Copyright The McGrawHill Companies Inc Permission required for reproduction or display 0 Substratum preconditioning o b ambient molecules y 0 0 0 d M W o o r ODesorption 0 o o 0 6 Gonvgdiquot 9 Detachment GCeII 0 and d39 us39ve o erosion and deposition transporj 0f 02 sloughing and nutrients o 0 g Q a GC t H o o g o 0 o e clelcretionhofd e oce p0 ysacc an e R I signaling 00 0 0 9 matrix R n and onset of g 9 Ce exopolymer 0 production I k adsorption a o OReplication K a 0 and growth 43 Biofilms Heterogeneous community metabolic differences location provide protection microbial interactions metabolic exchange DNA uptake Quorum sensing density dependent the chemical messengers may be secreted but don t make a difference unless there is a lot of them present 43 Copyright The McGrawHill Companies Inc Permission required for reproduction or display Negatively charged matrix 5 K g e 3 Positively charged Celltocell signals antrmrcroblal I binds to negatively charged slime 9 Change in physiology 00 Persister K Nutrient gradient Few cells lg gt nutrients 0 Anx Ox en radient 21 yg g gt Low 02 e Genetic diversity 5 39 Slow Fast growers growers vquot k 14 v 45 Problems Associated with Biofilms Permission required for reproduction or display Medical form on medical device cause disease dental caries Pneumonia Mixture of pus and microbes Industrial interfere with uids distribution Corrosion potential Rodney M Donlan and Emerging Infectious Diseases Figure 195b Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc Chapter 111 101 104 Microbial Nutrition and Metabolism warn rawmine WA REBEL Requirements for Microbial Survival and Growth Source of Energy for cellular work Source of electrons play a role in energy production reduce CO2 to form organic molecules Nutrients carbon hydrogen and oxygen to synthesize organic building blocks needed for cell maintenance and growth Energy and Electrons Sources organic or inorganic chemical compounds energy is obtained by oxidizingremoving electrons from a compound Sun light energy only Energy is usually conserved in cells as adenosine triphosphate ATP Sources of Energy Chemicals Chemotrophy Phototrophy Organic Inorganic chemicals chemicals glucose acetate etc H2 H25 Fe2 NH4 etc Chemoorganotrophs Chemolithotrophs Phototrophs glucose 02 gt CO2 H20 H2 02 H20 light M ATP 3 3 Figure 28 ATP ATP Figure 2 8 Brock Biology of Microorganisms 1 1 e 2006 Pearson Prentice Hall Inc Nutritional Types of Organisms Based on energy source Phototrophs use light Chemotrophs obtain energy from oxidation of chemical compounds Based on electron source Lithotrophs use reduced inorganic substances Organotrophs obtain electrons from organic compounds Nutritional Types Continued Based on carbon source Heterotrophs use organic molecules as carbon sources which often serve as energy and electron source as well Autotrophs use carbon dioxide as their sole or principal carbon source must obtain energy and electrons from other sources 66 o W prlmary producers Copyright The McGrawHill Companies Inc Permission required for reproduction or display Table 111 Sources of Carbon Energy and Electrons Carbon Sources Autotrophs Heterotrophs Energy Sources Phototrophs Chemotrophs Electron Sources Lithotrophs Organotrophs C02 sole or principal biosynthetic carbon source Reduced preformed organic molecules from other organisms Light Oxidation of organic or inorganic compounds Reduced inorganic molecules Organic molecules Copyright The McGrawHill Companies Inc Permission required for reproduction or display Table 112 Major Nutritional Types of Microorganisms Nutritional Type Photolithoautotroph Photoorganoheterotroph Chemolithoautotroph Chemoorganoheterotroph l Chemolithoheterotroph Carbon Source C02 Organic carbon C02 Organic carbon Organic carbon Energy Source Light Light Inorganic chemicals Inorganic chemicals Organic chemicals often same as C source Electron Source Inorganic e donor Organic e donor Inorganic e donor Inorganic e donor Organic equot donor often same as C source Representative Microorganisms Purple and green sulfur bacteria cyanobacteria diatoms Purple nonsulfur bacteria green nonsulfur bacteria Sulfuroxidizing bacteria hydrogen oxidizing bacteria methanogens nitrifying bacteria ironoxidizing bacteria Some sulfuroxidizing bacteria eg Beggiatoa Most nonphotosynthetic microbes including most pathogens fungi and many protists and archaea Microbial Metabolism metabolism total of all chemical reactions occurring in the cell Copyright the McGrawHill Companies Inc Permission required for reproduction or display TP A A Carbon source K Autotroph 002 Precursor Monomers L gtand other gtMacromolecules gt Heterotroph org anic moleCUIes 47 metaman building mocks Electron source Organotroph organic molecules gt Reducing power electrons Lithotroph inorganic molecules 3 Two Parts of Metabolism Catabolism Anabolism fueling reactions the synthesis of complex energy conserving organic molecules from reactions simpler ones provide ready source or 39 reclllil39BS Wand reducing power electrons quot111de bIOCkS from fuelin reactions generate precursors for g biosynthesis 1O Energy and Work Energy capacity to do work or to cause particular changes G free energythe amount of energy that is available to do useful work Delta G the change in energy that can occur in chemical reactions Types of work carried out by microorganisms chemical synthesis of new cellular material Transport take up of nutrients repair and replace elimination of wastes and maintenance of ion balances mechanical motility of cells chemotaXis 11 Standard Free Energy Change standard free energy change at E temperature of 25 C 1 atmosphere reactants and products at 1 M concentration Free Energy Change Exergonic reactions release energy AB 9 C D energy AG is negative reaction proceeds spontaneously Endergonic reactions require energy AB energy C D AG is positive reaction will not proceed spontaneously 13 Energy Currency of the Cell Copyright the McGraw Hill Companies Inc Permission required for reproduction or display 39 ATP easy to make and H2 Adenine lt1quot Krarr N easy to break gt About 31 kJmol 2 73 kcalmol of energy is released When ATP is hydrolyzed to ADP Pi gt About 46 kJmol of Adenosme monophosphate AMP energy ls r leased Adenosine diphosphate ADP When ls Adenosine triphosphate ATP hydrolyzed to 14 a Bond that releases energy when broken AMP 2 Pi Role of ATP in Metabolism Copyright the McGrawHill Companies Inc Permission required for reproduction or display Endergonic reaction alone AB CD Endergonic reaction coupled to ATP breakdown AB CD F 15 Copyright the McGrawHill Companies Inc Permission required for reproduction or display ADP Pi Aerobic respiration Chemical work Anaerobic respiration lgt lgt Transport work Fermentation Phototrophy Mechanical work Chemolithotrophy 16 HighEnergy Compounds NH2 CHO Ester N I Ester Anhyd rlde Anhydride bonds bond quoti gt Clo bond bond l N OHCH N o 0 3 39 3 0 CF II I Clquot2 C C00 0 PO PO P O CH HCIOH Ir H3C C 0 0 3 3 3 39339 CHzO o o 0 Ii 039 o Acetyl phosphate OH OH 0 Glucose 6phosphute Phosphoenolpyruvate Adenosme Irlphosphate ATP Thioester Compound 6039 kJmol bond o o 0 A60 gt 30k H u H H Phosphoenolpyruvate 561 ICH3CE S CH2239NIC CH22 N C CH23 l R 13Bisphosphoglycerate E493 a44g8 Acetyl BMercapto Pa ntothenic acid Acetyl phOSPhate ethylamine ATP ATP39 ADP Pi 305 ATP 456 ATP AMP 2 Pl A e39y39 can Acetyl CoA E31 AG 39 lt 30 AMP 391 42 Glucose 6phosphate 1 38 Figure 51 2 Brock Biology of Microorganisms 1 1e 2006 Pearson Prentice Hall Inc OxidationReduction RedoxReactions many metabolic processes involve redoX reactions electron transfer electron carriers are often used to transfer electrons from an electron donor to an electron acceptor can result in energy release which can be conserved as ATP or another energy rich compound OxidationReduction Oxidation Removal of an electron or electrons from a substance Example NAD Reduction Addition of an electron or electrons to a substance Example NADH H gtIltXidations and reductions frequently involve the transfer of not just electrons but both an electron e39 plus a proton H 19 39IH2gt2e39 2H Figure 58 part 1 Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc 2 02 2equot 02quot Electronaccepting half reaction Figure 58 part 2 Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc 3 2H 02 H20 Figure 58 part 3 Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc Electron Electron donor acceptor 439 H2 02 gt H20 Figure 58 part 4 Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc Standard Reduction Potential E o Equilibrium constant for an oxidation reduction reaction a measure of the tendency of the reducing agent to lose electrons more negative E390 better electron donor more positive E390 better electron acceptor Best electron donors Best electron acceptor Table 102 Selected Biologically Important Half Reactions Half Reaction 39 2H 2e gt H2 Ferredoxin Fe3 equot gt ferredoxin Fe2 NADP H 2e gt NADPH S 2H 2e39 gt H25 N Acetaldehyde 2H 2e39 gt ethanol Pyruvate 2H 2e39 gt lactatez 39 FAD 2H 2e gt FADHZ Oxaloacetatez39 2H 2e gt malatezquot Fumaratezquot 2H 2e gt succinatezquot Cytochrome b Fe3 equot gt cytochrome b Fe2 39 Ubiquinone 2H 2equot gt ubiquinone H2 Cytochrome c Fe3 e gt cytochrome c Fe2 l Cytochrome a Fe3 e gt cytochrome 0 Fe Cytochrome a3 Fe3 equot gt cytochrome a3 Fey N03 2H 2e gt NO H20 N0 8H 6equot gt NH4 ZHZO Fe3 e gt Fe 02 2H 2e gt H20 l 1 Egis the standard reduction potential at pH 70 E 2 Volts1 042 042 032 027 020 01 9 01 82 01 7 003 008 010 025 029 035 042 044 0773 082 2 The value for FADFADHZ applies to the free cofactor because it can vary considerably when bound to an apoenzyme 3 The value for free Fe not Fe complexed with proteins eg cytochromes l Negative Positive Electron Tower The greater the difference between the E390 of the donor and the E390 of the acceptor U the more negative the AGquot spontaneous energy released Copyright the McGrawHill Companies Inc Permission required for reproduction or display Better electron donors COZglucose 043 2HH2 042 COQmethanol 038 NADVNADH 032 Cogacetate 028 FADFADH2 018 Pyruvate lactate 01 9 Fumaratesuccinate 0031 CoQCoQH2 010 Cyt c Fe3Cyt c Fe2 0254 N0339N02 0421 N033912N2 074 Fe3Fe2 0771 1202 H20 0815 Better electron acceptors E6 Volts 05 04 03 02 01 00 01 02 03 04 05 06 07 08 09 10 2e NADH H 1202 H20 NAD A55 114 V Examples of reactions with H2 as e39 donor 1 H2 fumurate239 gt suuinutez39 Redox couple COzlglucose 043 24 e 2HIH2 042 2 e COZImethanol 038 6 equot NADINADH 032 2 e 1 COzlacetate 028 8 e AG 39 86 kJ 2 H2 quot0339 N02quot 2 s st 028 2 a 50427st 022 s e PyruvateIactate 019 2 equot 54062152032 0024 2 e 2 39 Fumaratelsuccinate 003 392 e Cytochrome boxm 0035 1 e vi AG 39 lb3 kl 3 H2 02 H20 AG 237 kJ Figure 59 Brock Biology of Microorganisms 11 e 2006 Pearson Prentice Hall Inc 3 I f Fe3lle2 02 1 e pH 7 Ubiquinoneoxhed 011 2 equot Cytochrome coxm 025 1 e Cytochrome acmed 039 1 e 39 NO3 IN02 042 2 equot N0339N2 074 5 e Fe3lle2 076 1 e39 pH 2 H 02H20 082 2 equot 15039 V I I 050 040 O30 020 010 39 00 010 quot39 020 030 040 050 060 070 080 090 Energy and Electron Flow in Metabolism ow of electrons More down the tower nega veEi NADH NADP releases energy r I I light energy is used to drive W s i L39gm genergyy electrons up the tower during photosynthesis 28 Aerobic respiration Oxygenic photosynthesis Electron Transport Chain ETC 0 electron carriers organized into ETC with the first electron carrier having the most negative E10 the potential energy stored in first redoX couple is released and used to form ATP first carrier is reduced and electrons moved to the next carrier and so on The net energy change of the complete reaction sequence is determined by the difference in reduction potentials between the primary donor and final acceptor 29 Electron Transport Chains Copyright the McGrawHill Companies Inc Permission required for reproduction or display Outer mitochondrial membrane Inner mitochondrial membrane Outer membrane Crista 75x r Cristae V l 39 Intermembrane space of matrix Intermembrane quot quot zz5 V 3 3 3 space outer quot vquot compartment I i C 39 39 39 I l I 39 l I v v c I a O 0 5 quot d I a u I a n 1 I n d 39 l 4 a a 39 0 b I o n 39 o ol 39 c 39 i v u v v u t n 39 quot Matrix inner compartment Matrix NADH dehydrogenase Cytochromes a and a3 most negative E6 leaSt negathe 50 a FMN Coenzyme Q Cytochrome b 30 Cell wall Plasma membrane with ETC NADH dehydrogenase most negative E5 Cytochromes a and a3 least negative E0 b Cytochrome c1 Cytochrome c Electron Carriers Two classes Coenzymes freely diffusible can transfer electrons from one place to another in the cell ex NAD Prosthetic groups firmly attached fixed to enzymes in the plasma membrane function in membrane associated electron transport reactions ex cytochromes NAD as a Redox Electron Carrier NAD nicotinamide adenine dinucleotide 39 NADP nieotinamide adenine dinucleotide phophate 39 NADH and NADPH are good electron donors reduction potential of redoX couple is O32 V NADNADH Coenzyme freely diffusible Carries 2 e39 plus 1 H 1 H is released Involved in catabolism NADPVNADPH works the same way except involved in anabolism NADH W m H HOl0 ltI I j 0 CH2 o N Ribose Adenine OH fH 39 Ho T O Phosphate added 0 in NADP Figure 510 Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc 34 NADNADH Cycling Reaction I Enzyme I reacts with substrate electron donor and oxidized form of coenzyme NAD NAD binding site Athe s39te Substrate electron l donor NAD x Substrate oxidized Enzyme and products Reaction 2 Enzyme Il reacts with substrate electron acceptor and reduced form of coenzyme NADH NADH Active binding site site NADH Substrate electron acceptor Enzymesubstrate complex 1 W NAD Substrate reduced Enzyme and products Figure 51 1 Brock Biology of Microorganisms 1 1e 2006 Pearson Prentice Hall Inc Chapter 112 113 116 118 Catabolism Energy Release and Conservation Electron Acceptors for Chemotrophic Processes Electrons released during the oxidation of chemical energy sources must be accepted by an electron acceptor Organic e39 donor Inorganic e39 donor Fermentation Aerobic Anaerobic Chemolithotrophy respiration respiration Endogenous 02 NO3 804239 02 304239 N03 organic 002 fumarate electron acceptor Exogenous electron acceptors Mechanisms of ATP Synthesis Substratelevel phosphorylation used in fermentation and other pathways ATP is synthesized during steps in the catabolism of an organic compound Xidative phosphorylation oxidation used in respiration anaerobic or aerobic ATP is produced by proton motive force Photophosphorylation used by phototrophic organisms Light drives the redoX reactions that generate the proton motive force Copyright The McGrawHill Companies Inc Permission required for reproduction or display Which molecule in a redox couple will likely serve as the electron acceptor in a reaction with a redox couple that has a more negative standard reduction potential E o 39 The oxidized one Intermediates in the lt biochemical pathway O u strute eve p osp ory atlon Figure 513a Brock Biology of Microorganisms 11e Energized membrane Oxidative phosphorylution Figure 513b Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc RESPIRATION most respiration involves use of an electron transport chain ETC 39 as electrons pass through the electron transport chain to the final electron acceptor a proton motive force PMF is generated and used to synthesize ATP oxidative phosphorylation TWO TYPES OF RESPIRATION aerobic respiration final electron acceptor is oxygen anaerobic respiration final electron acceptor is a different exogeneous acceptor such as N03 804239 C02 Fe3 or Se04239 organic acceptors may also be used ATP made primarily by oxidative phosphorylation FERMENTATION uses an endogenous electron acceptor such as pyruvate or derivative electron dump does NOT involve the use of an electron transport chain OR proton motive force ATP synthesized only by substratelevel phosphorylation Copyright The McGrawHill Companies Inc Permission required for reproduction or display Chemoorganotrophic Fueling Processes Aerobic respiration R 39 t39 39 esp39ra 390quot Electron transport chain ox phos PW ltgtO C Electron transport chain 8042 Anaerobic 39 N03 302 respiration atoms CO2 furnarate etc SLP Biosynthesis ADP Fermentation ADP QUE Biosynthesis C atoms Fermentation products eg ethanol H2 Beer Wlnea e39 39aCt39C aC39d yogurt biofuels Endogenous electron acceptors eg pyruvate 10 i O f Proteins Polysaccharides I Stage 1 Aeroblc Amino acids MonOsaccharides NADH Exoenzymes 1nduc1ble Stag t FADH I only turns genes on to digest quot3 quotx I I When they sense food is Pvmvate I NADH present aquot i II I AcetyHEOA zx Endoenzymes I constitutive always Stages oxa39oacel ate 0 onbeing produced 739 NADH 7L FADHm Tricarboxylic acid cycle lsocmam i y Stage 2 amp 3 CO I include amphibolic Ketogmtarate quot pathways catabolic z Coo and anabolic so can SL39CC YquotCOA CO 1 Cytochromes El t be broken down or quot33 built up chain 1 0L Aerobic Respiration process that can completely catabolize an organic energy source to C02 using 1 glycolytic pathway 2 TCA cycle 3 ETC with 2 as the final e39 acceptor produces ATP and recycles electron carriers 39 Produces intermediates for biosynthesis 13 ATP Production in Aerobic Respiration Maximum total yield gt g ATP Only 4 ATP molecules are synthesized directly from the oxidation of glucose substrate level phosphorylation A total of 28 ATP molecules are made When NADH and FADHZ are oxidized in ETC oxidative phosphorylation Electron Transport Chains Eukaryotes located in inner mitochondrial membrane Bacteria and Archaeons located in plasma membrane some resemble mitochondrial ETC but many are different 14 series of electron carriers that operate together transfer electrons from NADH and FADH2 to a terminal electron acceptor electrons ow from carriers with more negative E039 to carriers with more positive EO39 as electrons are transferred energy is released to make ATP by oxidative phosphorylation electron donors COZglucose 043 2H H2 042 COgmethanol 038 NADVNADH 032 COQacetate 028 SOHQS 027 Pyruvate lactate 019 FADFADH2 018 80327H2S 017 Fumaratesuccinate 0031 CoQCoQHQ 010 Cyt C Fe3Cyt c Fe2 0254 N03 N02 0421 NO239NH4 044 N0312N2 074 Fe3Fe2 0771 1402 H2O 0815 The Electron Transport Chain 435 04 03 02 01 00 01 02 03 04 05 06 07 08 ETC for P denitrificans Recall the difference in E039 between N ADH and 2 Large amount of energy released P 25 for NADH P LSt or FADHZ 0quot C o v o CY I39OPlASM 0 o o o o r3939 V 39 1 5 o quot39i 39 V y 39 g aI IF I 1 J I I C ENVIRONMENT Figure 520 Brock Biology of Microorganisms 1 1 e 2006 Pearson Prentice Hall Inc Proton Motive Force and the Chemiosmotic Hypothesis space 4H A I 4H t 2H NADH 4H NAD 4H H Matrix Movement of protons establishes PMF protons going out 2 1202 2H uses proton flow down gradient to make ATP IV H20 ATP synthase 3H F1 3H l1 CYTOPlASM I 1 J o op o 90090 ovoooooooooo coooooooooooquot i v s J o I39 ENVIRONMENT Figure 521 Brock Biology of Microorganisms 11e 2006 Pearson Prentice Hall Inc C12 18 Copyright The McGrawHill Companies Inc Permission required for reproduction or display Electron donors Electron Photosynthesis transport Proton motive force I ADP Pi 3 Bacterial Active flagella transport rotation Copyright The McGrawHill Companies Inc Permission required for reproduction or display Glucose GLYCOLYSIS Fructose 1 6 bis P04 l 2 Glyceraldehyde 3 P04 gt 2NADH I gt 5ATP Oxndative phosphorylation 2ATP Substratelevel phosphorylation 2 Pyruvate gt 2NADH gt 5ATP Oxidative phosphorylation 6NADH gt15ATP OXIdative phosphorylation gt 2FADH gt 3ATP 2 Oxidative phosphorylation 2 turns of TCA cycle gt 2ATP GTP Substratelevel phosphorylation Total aerobic yield 32ATP 19 20 Anaerobic Respiration uses electron carriers other than Q generally yields menergy because E0 of electron acceptor is less positive than E0 of 2 Copyright The McGrawHill Companies Inc Permission required for reproduction or display Table 113 Aerobic l Anaerobic Some Electron Acceptors Used in Respiration Electron Acceptor 02 N03 N03 5042 C02 C02 Fe3 HAso42 Se042 Fumarate Reduced Products H20 No Noz N20 N2 H25 CH4 Acetate H25 Fe2 HASOZ Se HSeO3 Succinate Examples of Microorganisms All aerobic bacteria fungi and protists Enteric bacteria Pseudomonas Bacillus and Paracoccus Desulfovibrio and Desulfotomaculum Methanogens Acetogens Desulfuromonas and Thermoproteus Pseudomonas Bacillus and Geobacter Bacillus Desulfotomaculum Sulfurospirilum Aeromonas Bacillus Thauera Wolinela 21 Fermentation takes place in the absence of an exogenous electron acceptor oxygen not needed uses pyruvate or derivative as endogeneous electron acceptor pyruvate is reduced continues recyclingof electron carriers NADH from glycolysis is oxidized to NAD forms ATP via substratelevel phosphorylation produces various fermentation products 22 Copyright The McGrawHill Companies Inc Permission required for reproduction or display Glycolysis Glucose NAD becomes reduced and releases a proton Gyceradehyde 3 NAD NAD NADH H NADH H 13 bisphosphogycerate Pyruvate Fermentation NADH H pathways N AD T Pyruvate puts the H Lactate proton X back on N AD NADH Fermentation Classes Ethanol breads Wine beer Lactic acid homolactic does NOTproduce gas like C02 0 Uses acid aldehyde to get pyruvate 0 Makes cheeses sour cream yogurt Heterolactic uses pinto phosphate to get to pyruvate Does make gasses like C02 Makes sauerkraut pickles buttermilk and involved in food spoilage 0 Mixed acid 23Butanediol involves VP test Voges Proskauer 23 Propionic acid I t 7 n T I Yn quot1quotquot 01111111 nLnnnn Sidebar Figure 51 Brock Biology of Microorganisms le 9 2006 Pearson Prentice Hall Inc Barton Spear Copyright The McGrawHill Companies Inc Permission required for reproduction or display FERMENTATION PATHWAYS Fumarate o L Mixed Acid several pathways 9 simultaneously 9 o Acetaldehyde CO2 AcetOin NADH 158 amp 9 002 002 Methyl Red test A detects pH 3 5 o 4W Acetaldehyde e 3 BUtanelel Acetyl lt1 AcetyICoA VogesProskauer test i I0 Acetoacetyi COA NADH detects Intermedlate L002 Acetone NADH acetoin 39 ButyryI CoA TV ButyryI CoA Pi GOA ADP NADH Butyraldehyde o NADH SW SS Cheese lt 3 m 1 Lactic acid bacteria Streptococcus Lactobacilus Bacillus enteric bacteria Escherichia Enterobacter Salmonella Proteus Enteric bacteria Enteric bacteria 2 Yeast Z ymomonas Clostridium 3 Propionic acid bacteria Propionibacterium 24 4 Enterobacter Serratia Bacillus Enteric bacteria LOODVOUUI Enteric bacteria 25 MRVP Test negative methy red 5 positive methy red MethylRed VogesProskauer UNIT 2 STUDY GUIDE Spring 2015 MICR 3050 OBJECTIVES Chapter 36 1 Describe the following bacterial structures and their functions cytoskeletal proteins and cell inclusions Chapter 37 39 2 3 4 5 6 Describe the following bacterial structures and their functions agella and endospores Describe agellar structure and movement Defme chemotaxis and describe how bacteria move toward an attractant or away from a repellent Describe other types of motility spirochete twitching and gliding Understand the structure and functions of bacterial endospores the basics of sporulation and germination and endospore resistance Chapters 111 101 104 11 12 l3 14 15 l6 l7 Know the requirements for microbial survival and growth and their sources Define and recognize the major nutritional types of microorganisms based on their energy source electron source and carbon source Defme metabolism catabolism and anabolism Understand the concepts of free energy G and standard free energy change A GO Distinguish between exergonic and endergonic chemical reactions and their relationship to A GO Explain the importance of ATP Be aware of other highenergy compounds and know the change in standard free energy requirement for cells to use them Understand redox reactions including the standard reduction potential Eo of half reactions the electron tower and their relationship to A GO Describe the location organization and functions of the Electron Transport Chains in bacteria De ne the two classes of electron carriers Describe how NADNADH and NADPNADPH carry electrons and their roles in metabolism Chapter 112 113 116 118 18 19 20 21 22 23 24 25 Compare and contrast aerobic respiration anaerobic respiration and fermentation in bacteria Compare and contrast substratelevel phosphorylation and oxidative phosphorylation Describe aerobic catabolism overview Describe the organization and functions of the electron transport chain in aerobic respiration including its role in ATP production Understand the Chemiosmotic Hypothesis Explain the function of ATP synthase Know the functions of proton motive force and how it is established For aerobic respiration explain where in the pathway ATP is produced glycolysis TCA cycle and ETC the methods of ATP production used for each ATP generated the electron carriers used and the number of ATPs produced during the process and the nal net yield 26 Describe the process of fermentation its functions and its products 27 Know why bacteria produce fermentation products and how these products are useful to humans 28 Distinguish between homolactic and heterolactic acid fermentation 29 Distinguish between mixed acid and butanediol fermentation 30 Explain the purpose of the MRVP test and know how it works Chapter 71 73 74 76 77 31 Describe the growth of bacterial cells binary fission 32 Describe in detail the four phases of bacterial growth observed in a batch culture 33 Be able to label a growth curve 34 Define generation time and be able to calculate it 35 Explain the methods of measuring the growth number of microbes microscopic count plating methods turbidity measurements 36 Describe how water activity pH temperature and oxygen affect microbial growth 37 Be able to name recognize and define the types of microorganisms that grow in various environments and know the adaptations they have made to live there 38 Explain how microorganisms protect themselves from the toxic products of oxygen reduction 39 Describe in general microbial growth in natural environments 40 Describe biofilms including their characteristics growth formation advantages for bacteria and disadvantages for humans Chapter 81 83 84 86 41 Know and describe the methods used to control microbial growth 42 Define the frequently used terms of microbial growth control 43 Describe the conditions that in uence the effectiveness of an antimicrobial agent 44 Explain how filters are used and their functions 45 Describe the physical methods to control microorganisms moist heat dry heat low temperature UV radiation ionizing radiation DISEASES 46 For each of the microbial diseases listed below be able to brie y describe the following a cause name of bacterium or virus b general characteristics of the microbe bacteria Gram reaction and shape viruses type of genome and shape c route of transmission d characteristic symptoms Strep Throat Streptococcal pharyngitis Cholera Bacterial Meningitis Meningococcal caused by N meningitidis Lyme Disease Infectious Mononucleosis Gas Gangrene Clostridial Myonecrosis caused by C perfringens Even if we do not cover these diseases in class you are still responsible for the information UNIT 2 ANIMATIONS TO WATCH http higheredmheducation com site s 007 3 3 7 526 8 studentviewO indeXhtml Chapter 3 Bacterial Locomotion ChemotaXis in E 001139 rst part only omit the part discussing the chemoreceptors involved Bacterial Endo Spore Formation httphigheredmheducationcomsitesOO734024OOstudentviewOindeXhtml Chapter 11 Electron Transport System and ATP Synthesis Electron Transport System and Formation of ATP How Glycolysis Works How NAD Works How the Krebs Cycle Works just watch for an overview Chapter 7 Binary Fission Bio lms NOTE Unless otherwise stated you are responsible for all of the unit objectives even if they are not covered in lecture see textbook Micro Test 2 Chapter 36 1 Describe the following bacterial structures and their functions cytoskeletal Proteins and cell inclusions Cytoskeleton plays a role in cell division protein localization and determination of cell shape 0 Protein examples I FtsZ zipper cell division I MinD makes sure FtsZ goes to middle before dividing prevents the polymerization of FtsZ at cell poles I CreS induces curvature in curved rods I MreB helps determine cell shape may be involved in chromosome segregation localizes proteins 0 Inclusions masses of organicinorganic material used for storage of nutrients 0 Examples granules crystals globules 0 Some have single layered membrane 0 Storage inclusions stores nutrients metabolic end products energy building blocks such as Carbon Phosphate Sulfur and Nitrogen o PHB is most common form of carbon storage 0 Gas vacuoles another type of inclusion provide buoyancy only in aquatic bacteria or archaea like little life jackets because they let gasses come and it helps the cell float They have different nutrients and different oxygen levels Aids in motility Magnetosomes magnetite particles for orientation in Earth s magnetic field 0 Helps cell go to the bottom of the water which is where nutrients are rich It does this by lining up with Earth s magnetic field Chapter 37 39 2 Describe the following bacterial structures and their functions flagella and endospores 0 External structure offers protection allows the ability to attach to surfaces horizontal gene transfer cell movement 0 Types fimbriae pili and flagella o Fimbriae and pili 0 Short thin hairlike appendages that allow attachment for surfaces 0 Type 4 pili may be required for motility twitching 0 Sex pili longer and thicker than fimbriae And less numerous Sex pili is required for conjugation for horizontal gene transfer 3 Describe flagella structure and movement 0 Flagella threadlike extensions that allow motility and swarming behavior attachment to surfaces and can be virulence factors to allow them to be better pathogens 0 Flagella is bigger than fimbriae and pili 0 Distribution 0 Monotrichous 1 flagellum 0 Polar flagellum 1 at one end 0 Amphitrichous 1 at both ends 0 Lophotrichous cluster of flagella at one or both ends 0 Peritrichous spread over entire surface 0 Cocci usually don t have flagellum 12 bacilli have it 0 Structure 0 Basal body includes rings motor I Includes C ring cytoplasm and MS ring membrane supra that DO spin I Also includes P ring in the peptidoglycan that does NOT spin 0 Hook extends from the L ring in LPS that does not spin The hook is hallow o Filament rigid and extends from hook o Gram negative has 4 rings Gram positive have 2 rings 0 Flagella has a 2 part motorto produce torque o Rotor C ring and MS ring both turn 0 Stator Mot A and Mot B proteins interact with the rings to cause propeller motion 0 Forward run counterclockwise o Clockwise 9 causes a stop and tumble 4 Define chemotaxis and describe how bacteria move toward an attractant or away from a repellent o Chemotaxis bacteria have rapid reflexes that the chemoreceptor causes depending on the concentrations of chemoattractants nutrientsfood or chemorepellants what the bacteria doesn t want to be close to This allows for the cell to move to or away from concentrations of chemicals 0 When it wants to go toward something it lowers the frequency of tumbles and runs for longer periods 0 To get away from something it causes more tumbles and shorter runs 5 Describe other types of motility spirochete twitching and gliding 1 Spirochete motility gram negative axia fibril made out of multiple flagella so that the new shape and gain in thickness can provide flexing and spinning movements 2 Twitching pili at ends so that when they move it s short jerky motions twitching done while in contact with other cells or surface 3 Gliding smooth movements produce slime some have little feet and slime 6 Understand the structure and functions of bacterial endospores the basics of sporulation and germination and endospore resistance 0 Endospore produced by bacteria It s complex and dormant It s resistant to many conditions such as heat radiation chemicals and drying out o The layers of an endospore start at exosporium outer shell then spore coat outer membrane cortex germ cell wall inner membrane core 0 An endospore is resistant because of the core has low water content CaDPA helps DNA to withstand environment and lower pH and the exosporium and spore coat is strong 0 Vegetative state normal state No spore 0 When there is a lack of nutrients the cell turns itself into a spore sporulation 0 But when nutrients are present the spore turns back into a cell so that it can increase metabolic activity and return to vegetative cell Chapters 111 101 104 7 Know the requirements for microbial survival and growth and their sources 0 Energy is needed for cellular work Electrons are needed for energy production and so that C02 can be reduced to organic molecules Nutrients such as 02 H2 and C are needed for cell maintenance and growth 0 Energy is obtained by oxidizing a compound 0 Sunlight provides energy 0 Energy is usually in cells as ATP 8 Define and recognize the major nutritional types of microorganisms based on their energy source electron source and carbon source 0 Based on energy source 0 Phototrophs get energy from light 0 Chemotrophs get energy from chemical compounds 0 Based on electron source 0 Lithotrophs electrons from inorganic substances 0 Organotrohps electrons from organic compounds 0 Based on Carbon source 0 Heterotrophs uses organic molecules 0 Autotrophs uses carbon dioxide Making them quotprimary producers 9 Define metabolism catabolism and anabolism o Metabolism total of all chemical reactions occurring in a cell 0 Catabolism provides source of power Breaks down molecules 0 Anabolism requires energy to make molecules 10 Understand the concepts of free energy G and standard free energy change A Go 0 Free energy G the amount of energy that is available to do useful work 0 Delta G free energy change the change in energy that can occur in chemical reactions 0 Delta G standard free energy under conditions 0 pH 7 o 25 C o 1 atm pressure 0 Reactants and products at 1 M concentrations 11 Distinguish between exergonic and endergonic chemical reactions and their relationship to A Go 0 Exergonic release energy 0 G negative spontaneous reactions 0 Endergonic requires energy 0 G positive not spontaneous 12 Explain the importance of ATP 0 Energy is stored in ATP bonds 0 31 kJmol of energy released when ATP is reduced to ADP 46 kJmol of energy is released when ATP is hydrolyzed to AMP 2 Pi 0 Many ways to make ATP 0 Aerobic respiration anaerobic respiration fermentation phototrophy chemolithotrophy 0 ATP is used for 0 Chemical work 0 Transport work 0 Mechanical work 13 Be aware of other highenergy compounds and know the change in standard free energy requirement for cells to use them 0 When electrons come together 0 More likely to be used by the cell if delta G is greater than 30 kJmol 14 Understand redox reactions including the standard reduction potential EO of half reactions the electron tower and their relationship to A Go o E 0 measure of tendency of reducing agent to lose electrons o Negative E better electron donor 0 Positive E better electron acceptor 0 Electron Tower 0 Greater difference in the donor and accept more negative Delta G 0 spontaneous energy released Energy released as electrons fall Photosynthesis causes electrons to travel UP the tower with light energy 15 Describe the location organization and functions of the Electron Transport Chains in bacteria 0 Electron Transport Chain 0 Carries electrons through a series of carriers with a primary donor and final acceptor o The greater different in the primary donor and final acceptor means more energy released In mitochondria for Eukaryotes In Archaean and Bacteria it s in the plasma membrane 16 Define the two classes of electron carriers Coenzymes freely diffusible can transfer electrons from one place to another in a cell Prosthetic groups firmly attached fixed to enzymes in the plasma membrane 0 Function in membrane ETC reactions 17 Describe how NADNADH and NADPNADPH carry electrons and their roles in metabolism 0 NADH and NADPH are good electron DONORS o Coenzymes o NAD amp NADH I Carriers 2 electrons plus 1 H I Involved in catabolism I Recycled o NADP amp NADPH I Carriers 2 e and 1 H I Involved in anabolism Chapter 112 113 116 118 18 Compare and contrast aerobic respiration anaerobic respiration and fermentation in bacteria 19 Compare and contrast substratelevel phosphorylation and oxidative phosphorylation 20 Describe aerobic cata bolism overview 21 Describe the organization and functions of the electron transport chain in aerobic respiration including its role in ATP production 22 Understand the Chemiosmosis Hypothesis 23 Explain the function of ATP synthase 24 Know the functions of proton motive force and how it is established 25 For aerobic respiration explain where in the pathway ATP is produced glycolysis TCA cycle and ETC the methods of ATP production used for each ATP generated the electron carriers used and the number of ATPs produced during the process and the final net yield 26 Describe the process of fermentation its functions and its products 27 Know why bacteria produce fermentation products and how these products are useful to humans 28 Distinguish between homolactic and heterolactic acid fermentation 29 Distinguish between mixed acid and butanediol fermentation 30 Explain the purpose of the MRVP test and know how it works Chapter 71 73 74 76 77 31 Describe the growth of bacterial cells binary fission 32 Describe in detail the four phases of bacterial growth observed in a batch culture 33 Be able to label a growth curve 34 Define generation time and be able to calculate it 35 Explain the methods of measuring the growth number of microbes microscopic count plating methods turbidity measurements 36 Describe how water activity pH temperature and oxygen affect microbial growth 37 Be able to name recognize and define the types of microorganisms that grow in various environments and know the adaptations they have made to live there 38 Explain how microorganisms protect themselves from the toxic products of oxygen reduction 39 Describe in general microbial growth in natural environments 40 Describe biofilms including their characteristics growth formation advantages for bacteria and disadvantages for humans Chapter 81 83 84 86 41 Know and describe the methods used to control microbial growth 42 Define the frequently used terms of microbial growth control 43 Describe the conditions that influence the effectiveness of an antimicrobial agent 44 Explain how filters are used and their functions 45 Describe the physical methods to control microorganisms moist heat dry heat low temperature UV radiation ionizing radiation DISEASES 46 For each of the microbial diseases listed below be able to briefly describe the following a cause name of bacterium or virus b general characteristics of the microbe bacteria Gram reaction and shape viruses type of genome and shape c route of transmission d characteristic symptoms 1 Strep Throat Streptococcal pharyngitis a Group A Streptococcus bacteria 4 i Gram positive ii b Transmission spread by persontoperson contact with fluids from the nose or saliva c Common symptoms include i Fever that may begin suddenly and is often the highest on the second day ii Chills iii Red sore throat that may have white patches iv Pain when swallowing v Swollen tender neck glands Cholera Cholera is an acute diarrheal illness caused by infection of the intestine with the bacterium Vibrio cholerae a Vibrio cholera gram negative comma shaped b Symptoms severe disease characterized by profuse watery diarrhea vomiting and leg cramps c Transmission found in water or food sources that have poop in it Bacterial Meningitis Meningococcal caused by N meningitidis a Neisseria meningitides i Gram negative coccus b Transmission Some bacteria can spread through the exchange eg by kissing of respiratory and throat secretions eg saliva or mucus c Symptoms i Nausea ii Vomiting iii Increased sensitivity to light photophobia and iv Altered mental status confusion v Stiff neck vL Fever vii Headache Lyme Disease spirochete a Bacteria spirochete Borrelia burgdorferi i Double membrane diderm NOT gram positive or gram negative b Bacterial infection c Transmission tick d Symptoms flulike symptoms at first i Migraines ii Arthritis iii Heart problems 5 Infectious Mononucleosis a Symptoms swollen necklymph nodes b quotkissing disease cuz transmitted by salvia c Caused by Epstein Barr virus i Most commonly found virus in world ii Part of herpes virus family 6 Gas Gangrene Clostridial Myonecrosis caused by C perfringens a C perfringens gram positive b Symptoms gas in tissues i Necrotic damage in muscle tissue c Transmission bacteria enters the body through broken skin or due to snake venom i Common in soldiers in 19005 because they sat in soil with infected injuries In class questions 0 Generation time know both equations 0 Gtn Generation time only comes from exponential log N 33logNtlogNO know the set up of the equations OOO I Log10quot5 5 Know that a cell will produce greater than 30 kJmol released if 30 then exergonic Know the different between standard reduction protential electron tower accepts at bottom donors at top and gibbs free energy 0 Redox Couples always written reducedoxidized o Electrons flow from down tower o The most negative delta G electron going all the way to the bottom more energy released 0 Left accepts right donates LARD Spoliation and germination don t need to know chart 0 Know what layers of endospores I What are layers 0 Core what is it Function 0 Inner Peptidoglycan Coretex peptidoglycan Outer membrane 0 Spore coat 0 What makes it resistant o What triggers sporulation I Lack of nutrients if growth stops usually because of lack of nutrients o What triggers germination I Presences of nutrients Know 3 FtsZ lines up in the middle to provide division plane MinD makes sure it s an even division Binary division how it works Know growth curves know difference and what happens in each one th tubes for oxygen requirements Know different of rings in gram negative and gram positive 0 1000 H required for one 360 degree turn Flagella hemostasis running rotation counterclockwise run clockwise tumble cannot run forever o If they are going in right direction longer runs and less tumbles o Tumbles change direction randomly Inclusion How many ATP are made for fermentation glycosis bridge step krebb cycle 0 Know for one molecule of glucose 32 net ATP aerobic respiration However not always 32 The 32 may not be reached because of o If you re a bacterium o How long the electron transport chain I Depends on species and nutrition 0 Things can be bled offtaken off for anabolism or building Proton motor force is used by oxidative phosphorylation FADHZ made through fermentation o Mrvp test 0 Homolactic vs heterolactic I And swiss cheese Fermentation produces acids which helps to preserve food Naming organisms based on energy carbon source 0 Organic organo Acetoin is intermediate tested by
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