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1 Copyright Notice!This PowerPoint slide set is copyrighted by Ross Koning and is thereby preserved for all to use from plantphys.info for as long as that website is available. Images lacking photo credits are mine and, as long as you are engaged in non-profit educational missions, you have my permission to use my images and slides in your teaching. However, please notice that some of the images in these slides have an associated URL photo credit to provide you with the location of their original source within internet cyberspace. Those images may have separate copyright protection. If you are seeking permission for use of those images, you need to consult the original sources for such permission; they are NOT mine to give you permission.1
4 Bacteria Eukarya Archaea 3 Domains A common ancestor Characteristics Figure 28-1 Page 567BacteriaEukaryaArchaea3 DomainsA common ancestorCharacteristicsplasma membranecell wallsDNA/RNA moleculesribosomesendosymbiosisCommon ancestor of allspecies living today
5 This view is incorrect! According to morphological Figure Page 577According to morphologicalsimilarities, prokaryotes shouldbe closely relatedBacteriaArchaeaEukaryaThis view is incorrect!
6 Size varies Shape varies Mobility varies Figure 28-13 Page 578 SmallLargeCompare relative sizesSize variesThe sizes of bacteria and archaea vary. Mycoplasmacells (left) are about 0.5 µm in diameter, while Thiomargaritanamibiensis cells (right) are about 150 µm in diameter.Shape variesThe shapes of bacteria and archaea vary fromrods such as Bacillus anthracis (left) and spheresto filaments or spirals such as Rhodospirillum.In some species, such as Streptococcus faecalis(right), cells attach to one another and form chains.Mobility variesA wide variety of bacteria and archaea use flagella (left)to power swimming movements. These cyanobacterialcells (right) move by gliding across a substrate.
7 Biology: What is Life? life study of Properties of Life Cellular Structure: the unit of life, one or manyMetabolism: photosynthesis, respiration, fermentation, digestion, gas exchange, secretion, excretion, circulation –processing materials and energyGrowth: cell enlargement, cell numberMovement: intracellular, movement, locomotionReproduction: avoid extinction at deathBehavior: short term response to stimuliEvolution: long term adaptation
8 Homeostasis - metabolism Nutrition ModeEnergy SourceCarbon SourcePhotoautotrophLightCO2ChemoautotrophInorganic chemPhotoheterotrophOrganic chemChemoheterotrophAll of these nutritional modes are found among prokaryotes!Eukaryotes are not as diverse in their nutritional modes.
9 Photoautotrophs - photosynthesis Ancient pathway, but not universalCyanobacteria, Algae, PlantslightCO2 + H2O O2 + CH2OchlorophyllPurple-sulfur bacteriaCO2 + H2S S2 + CH2O
10 Cyanobacterial Vegetative Cell cell wallmesosomecell membranecyanophycean starchphotosynthesis productcyanophycinvacuolelipid dropletpolyphosphate granulethylakoidslight reactionsnucleoidcytosolpolyhedral bodyCalvin cycle and starch synthesisRubisCO crystals!Prokaryotes do not have chloroplasts… they became chloroplasts!
11 Artificial coloration of TEM image But thylakoids shown as green would be natural!The location of bacteriochlorophyll!For the light reactions…In a light microscope image:Thylakoids would not be visible, so green color would appear throughout cytosol with the nucleoid region lighter in color.
13 Chemoautotrophs - N metabolism Cyanobacteria, Rhizobium - N2 fixationH+ + ATP + N2 NH4+Nitrosomonas - nitrification (forms nitrite)2 CO2 + NH4+ NO CH2OPseudomonas - denitrification2 CH2O + 2 NO2- N2 + 2 CO2 + 2 H2O√Which of these processes is demonstratingchemoautotrophism?
14 Nitrosomonas -internal membranes use NH4+ electrons in an ETS to produce ATPATP and protons used to reduce CO2 to CH2O
15 N O=O Rhizobium needs anaerobic conditions to convert N2 into NH4+ Legumes produce heme based molecules and rapid respiration to eliminate oxygen from root nodules that house the bacterium“symbiosis.”O=ONChemical similarity between these two molecules results in competitive inhibition of nitrogen fixation by oxygen.
17 Chemoheterotrophs - common! Escherichia coli and most eukaryotes…even plants!CH2O + O2 CO2 + H2O + ATPCarbohydrate, etc. provides boththe energy sourceandthe carbon sourceWhat is another chemoheterotrophic organism? Give the complete Latin binomial!
18 Chemoheterotrophy Aerobic Respiration CH2O + O2 CO2 + H2O Glycolysis carbohydrate to pyruvate (in cytosol!)Citric Acid Cycle pyruvate to carbon dioxide (in cytosol or matrix)Electron Transport and Oxidative Phosphorylation (in mesosomes or cristae)CH2O + O2 CO2 + H2OAnaerobic FermentationGlycolysis to pyruvate (in cytosol)Fermentive step(s) to return NAD+ to glycolysis (in cytosol)C6H12O6 C3H3O3- C2H5OH + CO2C6H12O6 C3H3O3- H3CCHOHCOO-Notice how fermentation can produce gas or acids…These are just a few of the fermentive possibilities!
19 Cyanobacterial Vegetative Cell I thought these were only photosynthetic??cell wallmesosomeelectron transport sytem and oxidative phosphorylationcell membranecyanophycean starchfuel for repirationcyanophycinvacuolelipid dropletfuel for repirationpolyphosphate granulethylakoidsIf its metabolism is facultative and the organism is in anaerobic conditions…nucleoidcytosolpolyhedral bodyglycolysis andKrebs cyclefermentation stepsProkaryotes do not have mitochondria… they became mitochondria!
20 Archaea have Homeostasis Facultative (can do both, but one better than another)and Obligate (strictly just one or the other) Anaerobes and AerobesNutrition ModeEnergy SourceCarbon SourcePhotoautotrophLightCO2ChemoautotrophInorganic chemPhotoheterotrophOrganic chemChemoheterotrophPhotoautotrophs use Calvin Cycle (Pyrococcus)Chemoautotroph use reverse TCA to fix CO2and sulfur transporters used drive ATP synthesisChemoheterotroph citric acid cycle, fermentation
21 Halobacterium NRC-1 Salt ponds where seawater is evaporating Figure Page 590Halobacterium NRC-1Salt ponds whereseawater isevaporatingThis red color is high population densities of Halobacterium salinarium!
22 Halobacterium salinarium 3 chromosomes:Main chromosome 2,015 kb191 kb replicon366 kb repliconReplicons have critical genes for:DNA polymeraseTranscription factorsMineral uptake (K, PO4)Cell divisionThe genome has many insertion sites for foreign genesHow do the 3 chromosomes migrate properly in binary fission?Bacteriorhodopsin:Protein + retinalAmax 280 UV, 570 green nmenergy for proton transport and phosphorylation without photosynthesis!Halobacterium salinariumAerobic RespirationUp to 5 M (25% NaCl)!Great Salt Lake, UtahRed Sea, Asia Minor
23 Hint: it reflects the other colors of the spectrum PeriplasmicspaceCellMembraneRetinallsu.epfl.ch/sh/bR_full.pdfCytoplasmBacteriorhodopsin absorbs green from the visible spectrum, so what color is the pigment?Hint: it reflects the other colors of the spectrumAlam/publications/PNAS96-ZHANG.pd
24 √ Which of these metabolic pathways is Halobacterium demonstrating? PhotoautotrophismPhotoheterotrophismChemoautotrophismChemoheterotrophism√Hint:Light for energyChemicals for carbon
25 Methanococcus jannischii Isolated from “white smoker”hydrothermal vent2600m deep on the East Pacific RiseMethanococcus.jpeg
28 Methanococcus jannischii Isolated from “white smoker”hydrothermal vent2600m deep on the East Pacific RiseMethanogenObligate anaerobeH2 as energy sourceCO2 as carbon sourceCH4 as byproduct of metabolismTemperature: 50-86°COther archaeon species found incow rumen (first stomach)Cow belches 50 L of methane per dayWhat does this electron micrograph tell you?…about cell shape?…about motility?
29 √ Which of these metabolic pathways is Methanococcus demonstrating? PhotoautotrophismPhotoheterotrophismChemoautotrophismChemoheterotrophism√Hint:H2 for energyCO2 for carbon
31 Sulfolobus acidocaldarius 75°C OptimumObligate aerobepH 1 to 6Oxidize Sulfur or can use Fe2+ or MnO42- as electron acceptors…uses glycolysis and TCA cycle(same path we have, but in a very different environment)
32 √ Which of these metabolic pathways is Sulfolobus demonstrating? PhotoautotrophismPhotoheterotrophismChemoautotrophismChemoheterotrophism√Hint:Organic chemicals for energyOrganic chemicals for carbon
33 How do Archaea tolerate the heat? Proteins stabilized by more ionic bridges between amino acid r-groups and more-hydrophobic core amino acidsHeat shock protein (chaperonins) refold denatured proteins…Pyrococcus 121°C for 1 hour!DNA depurination reduced by presence of 2,3-diphosphoglycerate.DNA supercoiling by reverse gyrase reduces denaturationSac7d in Sulfolobus is a minor groove protein increases the DNA melting temperature by 40°CHistone-like proteins help stabilize DNA as wellHeat-resistant di-bi-phytanyl diether lipid membranes (monolayer) prevent delamination of membrane
34 Cell Membrane Structure Composed of diglyceridesR group may be phosphate, sulfate, or sugarLong chain branched hydrocarbon (not fatty acid)Hydrocarbons may be C20 or C40If C20, the membrane is a bilayer:ORIf C40, the membrane is a monolayer:ORIn some species, the membrane is a mixture of both C20 and C40 diglycerides forming a mixed mono-/bi-layer.The C40 diglycerides prevent the bi-layer from de-laminating!
35 Thermus aquaticus Gram negative eubacterium Thermophile isolated from Not all thermophiles are archaeons!Thermus aquaticusGram negative eubacteriumThermophile isolated fromYellowstone Hot SpringOptimum temperature 85°CStability of macromolecules excellentEnzymes for research or commercial use Taq polymerase is the enzyme of PCR (Polymerase Chain Reaction)Lives near cyanobacteria which produce CH2O to feed Thermusag_franceschi/franceschi-projects-30S.html
36 √ Which of these metabolic pathways is Thermus demonstrating? PhotoautotrophismPhotoheterotrophismChemoautotrophismChemoheterotrophism√Hint:Organic chemicals for energyOrganic chemicals for carbon
37 Yellowstone National Park “Paint Pot” Thermophilic cyano-bacteria and eubacteria form a natural community of producers and consumers.
38 Yellowstone National Park “Paint Pot” Thermophilic cyanobacteria and eubacteria form a natural community of producers and consumers.
42 Gram-positive cells retain Gram stain more than Gram-negative cells do.Cell walls in Gram-positive bacteria have extensivepeptidoglycan.Cell walls in Gram-negative bacteria have somepeptidoglycan and an outer membrane.Gram-positivecell wallGram-negativecell wallGram-positivecellsPolysaccharidesPolysaccharidesGram-negativecellsCellwallCellwallOutermembranePeptidoglycanPeptidoglycanPlasmamembranePlasmamembraneProteinProtein
43 Gram-positive cells retain Gram stain more than Gram-negative cells do.
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