III. Cells and Energy. A. Energy Transfer in Cells 1.Carbohydrates such as glucose provide energy for the cell. However, they cannot be used directly,

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  • III. Cells and Energy

  • A. Energy Transfer in CellsCarbohydrates such as glucose provide energy for the cell. However, they cannot be used directly, They must be converted to ATPATP Adenosine Triphosphate is the energy molecule of the cell.

  • Adenosine Triphosphate

  • 3. How ATP works ATP links Anabolism (building molecules) and catabolism (breaking down molecules)!!!!!CatabolismATP is formed from ADP and Pi when energy is released by breaking the bonds of fuel molecules during cellular respirationAnabolismWhen ATP is broken down forming ADP and Pi energy is released to build molecules such as proteins

  • 4. How ATP is Produced: Respiration INOutGlucoseOxygenADPFree Phosphate(Pi) Carbon DioxideWaterMitochondrionThe ATP can be used directly to power life processes ATP

  • B. Capturing Light Energy: Photosynthesis 1. Requirements and products of photosynthesis INOutCarbon DioxideWaterLight EnergyGlucoseOxygenWaterChloroplast

  • 2. Stages of PhotosynthesisA) Light Reaction- traps light energy to make ATPLight strikes chlorophyll and electrons are boosted to a high energy stateElectrons flow down the electron transport chain and convert ADP to ATPB) Water is splitNADP captures hydrogen and becomes NADPHOxygen is given off as wasteC) The ATP and NADPH are used in the Dark reaction

  • A photon of light strikes chlorophyll and a water molecule is splitAs electrons move down the electron transport chain, hydrogen ions are pumped into thylkoid Light boost the electron to a NADP forming NADPHHydrogen ions flow through ATPsyntase forming ATP from ADP

  • 3. 2nd Stage of Photosynthesis: Dark Reaction- Uses the ATP from the light reaction to join the carbon dioxide (from the atmosphere) and hydrogen (from NADPH) to form glucose in a series of reactions called the Calvin CycleINOutCalvinCycleCarbon DioxideNADPHATPGlucoseNADPADP + Pi

  • The Calvin CycleCarbon dioxide joins with RuBP to form a six carbon moleculeThe six carbon molecule splits forming 3 carbon molecule called 3-PGAEnergy from ATP and hydrogen from NADPH are added forming G3POne molecule of 3GP exitsThe remaining molecule are converted to RuBP

  • C. Energy Release1. Anaerobic Respiration- the breakdown of glucose to produce 2ATP without using oxygen. a) Glycolysis- breaking glucose in two. This produces 2 ATP and Lactic acid1) Lactic acid causes muscle fatigue2) Lactic Acid produced by bacteria gives food a sour taste. Vinegar, sour cream, pickles etc BacteriaINOUTGlucose2(ADP + Pi)Lactic Acid2 ATP

  • Anaerobic Respiration b) Fermentation- breaking down glucose into Alcohol and Carbon Dioxide to produce 2 ATPFermentation produces beer and wineFermentation causes bread to riseYeastINOutGlucoseAlcoholCarbon Dioxide2ATP2(ADP + Pi)

  • Aerobic Respiration2. Aerobic Respiration- The break down of glucose with oxygen to produce 38 ATP. Involve 4 Steps: Step 1: Glycolysis (Occurs in cytoplasm)Glucose is broken in half producing Pyruvic Acid and 2 ATP

  • Step 2: Pyruvic Acid Conversion (in Mitochondria)Pyruvic acid is converted to Carbon Dioxide and Acetyl groupsCarbon DioxideAcetyl GroupsPyruvic Acid

  • Step 3: Krebs CycleThe Acetyl groups have their hydrogen stripped away releasing CO2 and 2 ATP

    Acetyl groupsHydrogenNADNADHCarbon Dioxide2 ATPKrebsCycle

  • Step 4: Electron Transport ChainHydrogen moves down the electron transport chain producing 34 ATP. The hydrogen then joins with oxygen to form water ADP + Pi34 ATP


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