chapter 9 how cells harvest chemical energy introduction to cell metabolism glycolysis aerobic cell...

Download Chapter 9 How Cells Harvest Chemical Energy Introduction to Cell Metabolism Glycolysis Aerobic Cell Respiration Anaerobic Cell Respiration

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  • Chapter 9How Cells Harvest Chemical EnergyIntroduction to Cell Metabolism

    Glycolysis

    Aerobic Cell Respiration

    Anaerobic Cell Respiration

  • O2CO2BREATHINGLungsCO2O2BloodstreamMuscle cells carrying outCELLULAR RESPIRATIONSugar + O2 ATP + CO2 + H2OBreathing and Cell Respiration are related

  • GlucoseOxygen gasCarbon dioxideWaterEnergyCellular Respiration uses oxygen and glucose to produce Carbon dioxide, water, and ATP.

  • Burning glucose in an experimentEnergy released from glucose (as heat and light)100%Energy released from glucose banked in ATPBurning glucose in cellular respirationAbout 40%Gasoline energy converted to movementBurning gasoline in an auto engine25%How efficient is cell respiration?

  • Loss of hydrogen atomsGlucoseGain of hydrogen atomsEnergyReduction and Oxidation

    OILRIG

    Oxidation is losing electrons

    Reduction is gaining electronsGlucose gives off energy and is oxidized

  • Reduction and Oxidation OILRIG Gain or loss of electrons is often in the form of hydrogen. The hydrogen is then passed to a coenzyme such as NAD+

  • Reduction and Oxidation

    What are some common co-enzymes? NAD+ and FADNAD+ + 2 H NADH + H+FAD + 2 H FADH2Remember that H = 2 electrons and 2H+

  • Reduction and OxidationThese co-enzymes are very important for cell respiration because they transfer high-energy electrons to electron transport systems (ETS).

  • Reduction and OxidationAs the electrons move from carrier to carrier, energy is released in small quantities.Electron transport system (ETS)

  • Generation of ATPThere are two ways to generate ATP

    Chemiosmosis

    Substrate-Level Phosphorylation

  • Generation of ATPChemiosmosis

    Cells use the energy released by falling electrons in the ETS to pump H+ ions across a membrane

    Uses the enzyme ATP synthase.

  • Generation of ATPChemiosmosis

  • ATP can also be made by transferring phosphate groups from organic molecules to ADPFigure 6.7BsubstrateproductEnzymeAdenosineAdenosineGeneration of ATPSubstrate Level Phosphorylation

  • ATP can also be made by transferring phosphate groups from organic molecules to ADPFigure 6.7BsubstrateproductEnzymeAdenosineAdenosineGeneration of ATPSubstrate Level Phosphorylation

  • General Outline GlucosePyruvic Acid GlycolysisOxygenAerobicNo OxygenAnaerobicTransition ReactionKrebs CycleETS38 ATPFermentation

  • Glycolysis

    Where? The cytosol

    What? Breaks down glucose to pyruvic acid

  • Glycolysis Steps A fuel molecule is energized, using ATP.131GlucoseStep234Glucose-6-phosphateFructose-6-phosphateGlyceraldehyde-3-phosphate (G3P) (TRIOSE PHOSPHATE)Step A six-carbon intermediate splits into two three-carbon intermediates.4Step A redox reaction generates NADH.551,3-Diphosphoglycerate (2 molecules)6Steps ATP and pyruvic acid are produced.693-Phosphoglycerate (2 molecules)72-Phosphoglycerate(2 molecules)82-Phosphoglycerate(2 molecules)9(2 molecules per glucose molecule)Pyruvic acidFructose-1,6-diphosphateEnergy In: 2 ATPEnergy Out: 4 ATPNET 2 ATP

  • General Outline GlucosePyruvic Acid GlycolysisOxygenAerobicNo OxygenAnaerobicTransition ReactionKrebs CycleETS36-38 ATPFermentation

  • General Outline of Aerobic Respiration Glycolysis

    Krebs CycleElectron Transport SystemTransition Reaction

  • Transition Reaction/Pre-Krebs/Link Reaction: Occurs in the Matrix

    Each pyruvic acid molecule is broken down to form CO2 and a two-carbon acetyl group, which enters the Krebs cycle. An Oxidative Decarboxylation Reaction:Acetyl CoAPyruvic Acid

  • General Outline of Aerobic Respiration Glycolysis

    Krebs CycleElectron Transport SystemTransition Reaction

  • Krebs Cycle

    Where? In the Mitochondria

    What? Uses Acetyl Co-A to generate ATP, NADH, FADH2, and CO2.

  • Krebs Cycle

  • Krebs Cycle

  • General Outline of Aerobic Respiration Glycolysis

    Krebs CycleElectron Transport System

  • Electron Transport SystemFigure 6.12Intermembrane spaceInner mitochondrial membraneMitochondrial matrixProtein complexElectron carrierElectron flowELECTRON TRANSPORT CHAINATP SYNTHASE

  • Electron Transport System

  • CHEMIOSMOSISThe coupling of ATP synthesis to electron transport via a concentration gradient.

    It is the MECHANISM for oxidative phosphorylation in Aerobic C.R. and Photosynthesis

  • Electron Transport SystemFor each glucose molecule that enters cellular respiration, chemiosmosis produces up to 38 ATP molecules

  • Overview of Aerobic Respiration

  • General Outline GlucosePyruvic Acid GlycolysisOxygenAerobicNo OxygenAnaerobicTransition ReactionKrebs CycleETS38 ATPFermentation

  • FermentationRequires NADH generated by glycolysis.Where do you suppose these reactions take place?Yeast produce carbon dioxide and ethanolMuscle cells produce lactic acidOnly a 2 ATP are produced per glucose

  • Fermentation

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