Energy ReviewEnergy Storing MoleculesATP, NADPH (NAD+), FADH (FAD+), FADH2ATP supplies most of the energy that drives metabolism in living thingsATP releases energy when converted into ADP
Cellular Respiration Overview
Living things get most of the energy they need from glucose.Autrotrophs make glucose using photosynthesisHeterotrophs get glucose from food they eatCellular RespirationThe process that releases energy by breaking down glucose and other food molecules in the presence of oxygen.
Cellular Respiration OverviewCellular Respiration Overall Equation6O2 + C6H12O6 6CO2 + 6H2O + EnergyThree StagesGlycolysisKrebs CycleElectron Transport ChainThe Main form of Energy produced = ATP
GlucoseGlycolysisCytoplasmPyruvic acidElectrons carried in NADHKrebs CycleElectrons carried in NADH and FADH2Electron Transport ChainMitochondrionFigure 92 Cellular Respiration: An OverviewMitochondrion
GlycolysisGlyco = Glucoselysis = BreakdownOccurs in the cytoplasm of the cellMolecules of GLUCOSE are broken down into 2 molecules of Pyruvic Acid.Cell must use (invest) 2 ATPProduces Energy Carrier Molecules4 ATP2 NADH
GlycolysisPyruvate = Pyruvic Acid
GlycolysisGlucosePyruvic AcidPyruvic AcidTo the Electron Transport Chain
The Mighty MitochondriaThe mitochondria is the organelle where the final stages of cellular respiration occurs.Krebs CycleElectron Transport ChainCells that use a lot of energy have high numbers of mitochondria.Example: Muscle cells in the heart!!
Aerobic Process = Only if oxygen is present!!Occurs in the MATRIX of the mitochondriaPyruvic Acid from Glycolysis enters to form1 ATP3 NADH1 FADH2CO2 (which is released when we exhale!!)AKA.Citric Acid Cycle
Electron Transport Chain
Energy carrier molecules produced during Glycolysis and the Krebs Cycle enter the ETCNADHFADH2Occurs in the folds of the Inner Membrane of the Mitochondria (Cristae)The electrons are passed down a chain of proteins until they reach the final electron acceptor..oxygen!So this step is aerobic (requires oxygen)The ETC produces 32 ATP and H2O
Electron Transport ChainThe chain then repeats in the same way with FADH2
Cellular Respiration FlowchartSection 9-2Glucose (C6H1206)+Oxygen (02)GlycolysisKrebs CycleElectron Transport ChainCarbon Dioxide(CO2)+Water(H2O)
What happens if
is available??The Krebs Cycle and Electron Transport Chain cant function!!These are anaerobic conditions!!
The cell can use Fermentation instead!!Occurs in the CytoplasmJust like glycolysis!!FermentationA series of reactions that convert NADH (from glycolysis) back into NAD allowing glycolysis to keep producing a small amount of ATP
2 Types of FermentationAlcoholic FermentationYeasts use this process to form ethyl alcohol and carbon dioxide as waste products.This causes bread dough to riseThis is how some alcoholic beverages are made
Pyruvic Acid + NADH alcohol + CO2 + NAD+
Lactic Acid FermentationOccurs in bacteria (unicellular organisms)This is how cheese, yogurt, and pickles are made.Occurs in muscles during rapid exerciseWhen your body runs out of oxygen your muscle cells must produce some ATP using fermentation and glycolysisLactic Acid build-up causes muscle soreness or burning after intense activity.Pyruvic Acid + NADH lactic acid + NAD+
Fermentation SummaryGlycolysis: Glucose 2 Pyruvic AcidFermentation: 2 Pyruvic Acid alcohol or lactic acid
Chemical PathwaysGlucoseGlycolysis Krebs cycle Electron transportFermentation (without oxygen)Alcohol or Lactic AcidSection 9-1