Microbial Metabolism Ch 5Microbial MetabolismAmphibolic pathwaysSlide 4PowerPoint PresentationBiochemical testsEnzymesSlide 8Slide 9Important CoenzymesSlide 11Factors Influencing Enzyme ActivitySlide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19The Generation of ATPSlide 21Slide 22Metabolic PathwaysCarbohydrate CatabolismGlycolysisPreparatory StageEnergy-Conserving StageSlide 28Alternatives to GlycolysisCellular RespirationIntermediate StepKrebs CycleSlide 33The Electron Transport ChainChemiosmosisElectron transport and ChemiosmosisSlide 37RespirationAnaerobic respirationSlide 40Slide 41Slide 42FermentationSlide 44Slide 45Slide 46Slide 47Lipid CatabolismProtein CatabolismSlide 50Slide 51ChemotrophsSlide 53Metabolic Diversity Among OrganismsMetabolic Pathways of Energy UseSlide 56Slide 57Slide 58Slide 59Slide 60Slide 61Microbial MetabolismCh 5•Metabolism is the sum of the chemical reactions in an organism.•Catabolism is the energy-releasing processes.•Anabolism is the energy-using processes. (typically building something)•Catabolism provides the building blocks and energy for anabolism.Microbial MetabolismFigure 5.1•Are metabolic pathways that have both catabolic and anabolic functions.–This is basically all of lifeAmphibolic pathwaysFigure 5.32.1Amphibolic pathwaysFigure 5.32.2•A metabolic pathway is a sequence of enzymatically catalyzed chemical reactions in a cell.•A primary metabolic pathway are the reactions that do the basic work of the cell. Get food and grow•Metabolic pathways are determined by enzymes.•Enzymes are encoded by genes.Biochemical testsFigure 10.8•Used to identify bacteria.•Enzymes are genes•Sum of genes is your organismEnzymesFigure 5.2•Biological catalysts–Specific for a chemical reaction; not used up in that reaction•Apoenzyme: protein•Cofactor: Nonprotein component–Coenzyme: Organic cofactor•Holoenzyme: Apoenzyme + cofactorEnzymesEnzymesFigure 5.3•NAD+•NADP+•FAD•Coenzyme A•Biotin•Folic acid•Many of the vitaminsImportant Coenzymes•The turnover number is generally 1-10,000 molecules per second.EnzymesFigure 5.4•Enzymes can be denatured by temperature and pHFactors Influencing Enzyme ActivityFigure 5.6•TemperatureFactors Influencing Enzyme ActivityFigure 5.5a•pHFactors Influencing Enzyme ActivityFigure 5.5b•Substrate concentrationFactors Influencing Enzyme ActivityFigure 5.5c•Competitive inhibitionFactors Influencing Enzyme ActivityFigure 5.7a, bFactors Influencing Enzyme ActivitySulfa inhibits the enzyme that uses PABA for synthesis of folic acid•Noncompetitive inhibitionFactors Influencing Enzyme ActivityFigure 5.7a, c•Feedback inhibitionFigure 5.8•ATP is generated by the phosphorylation of ADP.The Generation of ATP•Substrate-level phosphorylation is the transfer of a high-energy PO4- to ADP. The Generation of ATP•Energy released from the transfer of electrons (oxidation) of one compound to another (reduction) is used to generate ATP by chemiosmosis.The Generation of ATPMetabolic Pathways•The breakdown of carbohydrates to release energy–Glycolysis–Krebs cycle–Electron transport chainCarbohydrate Catabolism•The oxidation of glucose to pyruvic acid, produces ATP and NADH.Glycolysis•2 ATPs are used•Glucose is split to form 2 Glyceraldehyde-3-phosphatePreparatory StageFigure 5.12.1PreparatoryStageGlucoseGlucose6-phosphateFructose6-phosphateFructose1,6-diphosphateDihydroxyacetonephosphate (DHAP)Glyceraldehyde3-phosphate(GP)12345•2 Glucose-3-phosphate oxidized to 2 Pyruvic acid•4 ATP produced•2 NADH producedEnergy-Conserving StageFigure 5.12.21,3-diphosphoglyceric acid3-phosphoglyceric acid2-phosphoglyceric acidPhosphoenolpyruvic acid(PEP)678910Pyruvic acid•Glucose + 2 ATP + 2 ADP + 2 PO4– + 2 NAD+  2 pyruvic acid + 4 ATP + 2 NADH + 2H+Glycolysis•Pentose phosphate pathway:–Uses pentoses and NADPH–Operates with glycolysis–Use and production of 5 carbon sugars (na)–Bacillus subtilis, E. coli, Enterococcus faecalis•Entner-Doudoroff pathway: –Produces NADPH and ATP–Does not involve glycolysis–Pseudomonas, Rhizobium, AgrobacteriumAlternatives to Glycolysis•Oxidation of molecules liberates electrons for an electron transport chain•ATP generated by oxidative phosphorylationCellular Respiration•Pyruvic acid (from glycolysis) is oxidized and decarboyxlatedIntermediate StepFigure 5.13.1•Oxidation of acetyl CoA produces NADH and FADH2Krebs CycleKrebs CycleFigure 5.13.2•A series of carrier molecules that are, in turn, oxidized and reduced as electrons are passed down the chain.•Energy released can be used to produce ATP by chemiosmosis.The Electron Transport ChainChemiosmosisFigure 5.15Electron transport and ChemiosmosisFigure 5.16.2Figure 5.14•Aerobic respiration: The final electron acceptor in the electron transport chain is molecular oxygen (O2).•Anaerobic respiration: The final electron acceptor in the electron transport chain is not O2. Yields less energy than aerobic respiration because only part of the Krebs cycles operations under anaerobic conditions.RespirationAnaerobic respirationElectron acceptor ProductsNO3–NO2–, N2 + H2OSO4–H2S + H2OCO32 –CH4 + H2O•Energy produced from complete oxidation of 1 glucose using aerobic respirationPathwayATP producedNADH producedFADH2 producedGlycolysis 2 2 0Intermediate step0 2Krebs cycle 2 6 2Total 4 10 2• ATP produced from complete oxidation of 1 glucose using aerobic respiration•36 ATPs are produced in eukaryotes.PathwayBy substrate-level phosphorylationBy oxidative phosphorylationFrom NADHFrom FADHGlycolysis 2 6 0Intermediate step0 6Krebs cycle 2 18 4Total 4 30 4Pathway Eukaryote ProkaryoteGlycolysis Cytoplasm CytoplasmIntermediate step Cytoplasm CytoplasmKrebs cycleMitochondrial matrixCytoplasmETCMitochondrial inner membranePlasma membrane•Releases energy from oxidation of organic molecules• Does not require oxygen• Does not use the Krebs cycle or ETC• Uses an organic molecule as the final electron acceptorFermentationFermentationFigure 5.18b•Alcohol fermentation. Produces ethyl alcohol + CO2•Lactic acid fermentation. Produces lactic acid.–Homolactic fermentation. Produces lactic acid only.–Heterolactic fermentation. Produces lactic acid and other compounds.FermentationFermentationFigure 5.19FermentationFigure 5.23Production of acid and gasLipid CatabolismFigure 5.20Protein CatabolismProtein Amino acidsExtracellular proteasesKrebs cycleDeamination,