Presentation on theme: "Biology: What is Life? life study of Properties of Life"— Presentation transcript:
1Biology: 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
2Homeostasis - metabolism Nutrition ModeEnergy SourceCarbon SourcePhotoautotrophLightCO2ChemoautotrophInorganic chemPhotoheterotrophOrganic chemChemoheterotrophAll of these nutritional modes are found among prokaryotes!Eukaryotes are not as diverse in their nutritional modes.
3Photoautotrophs - photosynthesis Ancient pathway, but not universalCyanobacteria, Algae, PlantslightCO2 + H2O O2 + CH2OchlorophyllPurple-sulfur bacteriaCO2 + H2S Ss + CH2O
5Artificial 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 nucleoid region lighter in color
6Chemoautotrophs - N metabolism Cyanobacteria, Rhizobium - N2 fixationH+ + ATP + N2 NH4+Nitrosomonas - nitrification2 CO2 + NH4+ NO CH2OPseudomonas - denitrification2 CH2O + 2 NO2- N2 + 2 CO2 + 2 H2O√Which of these processes is demonstratingchemoautotrophism?
7Nitrosomonas -internal membranes use NH4+ electrons in an ETS to produce ATPATP and protons used to reduce CO2 to CH2O
8Rhizobium 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”
10Chemoheterotrophs - 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!
11Chemoheterotrophy 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!
12Cyanobacterial Vegetative Cell I thought these were only photosynthetic??cell wallmesosomeelectron transport sytem and oxidative phosphorylationcell membranecyanophycean starchfuel for repirationcyanophycinvacuolelipid dropletfuel for repirationpolyphosphate granulethylakoidsnucleoidcytosolpolyhedral bodyglycolysis andKrebs cycleProkaryotes do not have mitochondria…they became mitochondria!
13Archea have Homeostasis Facultative and Obligate Anaerobes and AerobesNutrition ModeEnergy SourceCarbon SourcePhotoautotrophLightCO2ChemoautotrophInorganic chemPhotoheterotrophOrganic chemChemoheterotrophPhotoautotroph Calvin Cycle (Methanococcus, Pyrococcus)Chemoautotroph acetyl-CoA or reverse TCA to fix CO2Sulfur transporters used to drive ATP synthesisChemoheterotroph citric acid cycle, fermentation
14Replicons have genes for: DNA polymerase Transcription factors 3 chromosomesMain chromosome 2,015 kb191 kb replicon366 kb repliconReplicons have genes for:DNA polymeraseTranscription factorsMineral uptake (K, PO4)Cell divisionThe genome has many insertion sitesfor foreign genesBacteriorhodopsin:Protein + retinalAmax 280 UV, 570 green nmenergy for proton transport and phosphorylation without photosynthesis!Halobacterium salinariumarchaea/halobacterium/halobacteria_1.jpgAerobic RespirationUp to 5 M (25% NaCl)!Great Salt Lake, UtahRed Sea, Asia Minor
15Hint: 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
16√ Which of these metabolic pathways is Halobacterium demonstrating? PhotoautotrophismPhotoheterotrophismChemoautotrophismChemoheterotrophism√Hint:Light for energyChemicals for carbon
17Methanococcus jannischii Isolated from “white smoker”hydrothermal vent2600m deep on the East Pacific Rise
20Methanococcus 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?
21√ Which of these metabolic pathways is Methanococcus demonstrating? PhotoautotrophismPhotoheterotrophismChemoautotrophismChemoheterotrophism√Hint:H2 for energyCO2 for carbon
22Sulfolobus acidocaldarius 75°C OptimumStrict aerobepH 1 to 6Oxidize Sulfur or can use Fe2+ or MnO42- as electron acceptors…uses glycolysis and TCA cycle
23√ Which of these metabolic pathways is Sulfolobus demonstrating? PhotoautotrophismPhotoheterotrophismChemoautotrophismChemoheterotrophism√Hint:Organic chemicals for energyOrganic chemicals for carbon
24How 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 melting temperature by 40°CHistone-like proteins help stabilize DNA as wellHeat-resistant di-bi-phytanyl diether lipid membranes (monolayer) prevent delamination of membrane
25Cell 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 monolayerORIn some species, the membrane is a mixture of both C20 and C40 diglycerides forming a mixed mono-/bi-layer
26Thermus aquaticus Gram negative bacterium (not archaeon) Thermophile isolated fromYellowstone Hot SpringOptimum temperature 85°CStability of macromolecules excellentEnzymes for research or commercial useTaq polymerase is the enzyme of PCR (Polymerase Chain Reaction)Lives near cyanobacteria which feed Thermusag_franceschi/franceschi-projects-30S.html
27√ Which of these metabolic pathways is Thermus demonstrating? PhotoautotrophismPhotoheterotrophismChemoautotrophismChemoheterotrophism√Hint:Organic chemicals for energyOrganic chemicals for carbon