Cellular Respiration The Energy in Food. Cellular Respiration Cellular Respiration – A chemical process that uses oxygen to convert the chemical energy

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  • Cellular Respiration The Energy in Food

  • The Energy in FoodCellular Respiration A chemical process that uses oxygen to convert the chemical energy stored in foods (organic molecules) into another form of chemical energy.ATP Adenosine Triphosphate Cells in plants and animals use ATP as their main energy supply

  • The Energy in FoodRapid Oxidation the release of chemical energy by burningThis reaction is not controlled by enzymesResults consist of an uncontrolled energy release

  • The Energy in FoodSlow Oxidation the release of energy in a controlled fashion. Enzymes catalyze a sequence of events that cause covalent bonds to break one at a time.This is Metabolism!

  • Photosynthesis / Cellular Respiration Recycle a common set of chemicals:WaterCarbon DioxideOxygenGlucose (Organic Compounds)

  • ATPPhosphate part is most importantBecause of the negative charge on all the attached oxygens, there is a lot of potential energy in these bondsRemoving the last phosphate group makes the molecule much happier (chemically stable)

  • ATP to ADP

  • Three Types of work that Cells Perform ReviewChemical WorkBuilding large molecules like proteinsATP provides energy for Dehydration Synthesis

  • Three Types of work that Cells Perform ReviewMechanical WorkMuscle ContractionATP causes change in shape of protein which then opens the door for Potassium (K) and Calcium (Ca) to cause the binding of Actin and Myosin.

  • Three Types of work that Cells Perform ReviewTransport WorkPumping Ions across a membrane

  • RespirationOrganic compounds contained stored (potential) chemical energy in their bondsWhen that energy is released, cells can use it for metabolismGlucose (from glycogen stores) typically used first as the source of energyNo glucose? Lipids next then amino acids/proteins (only in extreme cases- i.e. starvation)

  • RespirationControlled release of energy from organic compounds in cells to form: Adenosine Triphosphate (ATP)Glycolysis is the first step in respirationTwo types of respiration: Aerobic (uses oxygen) Anaerobic (without oxygen)2 types of anaerobic respiration: Lactic Acid Fermentation (Humans / Mammals) Alcoholic Fermentation (yeast)

  • Anaerobic RespirationLactic Acid FermentationNormally in aerobic organisms that find themselves in a situation where oxygen is no longer availablewhy you breather harder when you work outWhen O2 becomes available, lactate converted back to pyruvate and then pushed through the aerobic pathwayPyruvate converted to lactate (3-C), no CO2 produced, no ATP produced

  • Anaerobic RespirationLactic Acid FermentationDOES NOT MAKE YOU SORENO ATP IS MADE SO IT DOES CAUSE FATIGUE

  • Anaerobic RespirationAlcoholic FermentationOccurs in yeast cellsThis is a normal situation for the yeastPyruvate converted to ethanol (2-C) and CO2 is releasedboth waste products for the organismBakers and brewers yeast allows bread to rise and beer to be carbonated (most commercial beer is forcibly carbonated as well)

  • Fermentation in Microorganisms

  • Oxygen and Cellular RespirationBreathing and Cellular RespirationAerobic Process means it requires oxygenCells Exchange: Oxygen into the cellCarbon Dioxide out of the cell

    Body: In your lungs Blood Exchange: Oxygen (in) Carbon Dioxide (out)

  • Cellular RespirationChemical Formula:Each glucose molecule yields 38 ATP molecules

  • Reviewing the MitochondriaFound in almost all Eukaryotic CellsThe Mitochondria structure is key to its role in cellular respirationHave their own DNAHave their own ribosomes

  • MitochondriaStructure: Made up of two membranes There is a space between the inner and the outer membraneMatrix the highly folded inner membrane enclosing a thick fluid Inside the inner membrane you find many of the enzymes involved in cellular respiration folds of the membrane allows a Large Surface Area for reactions to occur.MAXIMIZES the area for ATP production

  • Cellular RespirationFirst:Metabolism all chemical processes in a cellMetabolic Pathways Term given to cellular respiration; because it is made up of a series of reactions (thus the term pathways)Specific enzymes catalyzes each reactions in a pathways

  • The Metabolic PathwaysThree Steps or StagesStage 1: Glycolysis = Splitting SugarFirst stage in breaking down glucose moleculeTakes PLACE outside the mitochondria in the cytoplasm2 ATP molecules are actually used to get things started.2 ATPs split the glucose molecule in half.

    Investment StageElectrons are then transferred to a carrier molecule called NAD NAD then turn into NADH At this point 4 ATP are produced Now your up by 2 ATP

  • The Metabolic PathwaysGlycolysis (Payback Stage)Remember you used 2 ATPs to startGained 4 (net gain)End Result are:

    Two Pyruvic Acid Molecules

    Glucose + 2ATP 2 Pyruvic Acid molecules + 4ATP Pyruvic Acid Molecules still hold most of the energy of the original glucose molecules

  • The Metabolic PathwaysStage 2: The Kreb CycleNamed after biologist Hans KrebsBlame this guy

  • The Metabolic PathwaysThe Kreb CycleFinishes the breakdown of Pyruvic Acid molecules to CO - releasing more energy.Pyruvate loses a C as CO2, becomes acetyl-CoAEnzymes are dissolved in the Matrix inside the MatrixCalled the Fluid Matrix

  • The Metabolic PathwaysAcetyl Co A joins a 4 Carbon Acceptor moleculeProduces 2 CO + 1 ATP per Acetyl CoANADH and FADH (another electron carrier) trap most of the energyAt the end you are left with a 4 carbon acceptor molecule So the cycle can continue

    The Kreb Cycle

  • The Metabolic Pathways

  • The Metabolic PathwaysThe Kreb CycleResults:Glycolysis produces 2 Pyruvic Acid molecules from 1 glucose moleculeEach Pyruvic Acid molecule makes 1 Acetyl CoACycle turns 2 TIMESProducing: 4 CO + 2ATPs

  • The Metabolic PathwaysElectron Transport Chain & ATP Synthase ActionFirst: (carrier molecules) NADH transfers electrons from the original glucose molecule to an electron transport chain.Remember: e move to carriers that attract them more stronglyThis is why they move from carrier to carrierOne carrier attracts them more than the one carrying; moving the e to the inner mitochondria Finally being pulled by oxygen at the end of the chain.2 H combines with oxygen forming HO

  • The Metabolic PathwaysElectron Transport Chain & ATP Synthase Action

  • The Metabolic PathwaysElectron Transport Chain & ATP Synthase ActionATP Synthase Protein structures inside the mitochondria that receives the H uses that flow to convert ADP into ATP.Can make up to 34 ATPs

  • The Final CountGlycolysis 2 ATPKreb Cycle 2 ATPElectron Transport Chain 34 ATPMaximum ATP for 1 Glucose Molecule = 38Notice most ATP is made after Glycolysis and Kreb Cycle which are anaerobic (without O)

  • Aerobic respiration

  • Types of RespirationOccurs in the absence of OxygenAerobic RespirationOccurs in presence of OxygenOccurs in the cells cytoplasmOccurs in the cells mitochondria Yields small amount of ATP (2 molecules) per molecule of glucoseYields large amount of ATP (38 molecules) per molecule of glucoseDoes not involve fermentationInvolves fermentation of pyruvate to lactate in muscles/CO2 & ethanol in plant & yeastAnaerobic Respiration

  • Comparison between Aerobic & Anaerobic Respiration -Animals


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