Cell Energy Photosynthesis and Respiration. How do Cells Store Energy? Adenosine Triphosphate (ATP) – the molecule where the energy is stored for cell.

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  • Cell EnergyPhotosynthesis and Respiration

  • How do Cells Store Energy?Adenosine Triphosphate (ATP) the molecule where the energy is stored for cell processes.NADP+ and NADPH- carrier molecules that carry high energy electrons for reactions in the cell.

  • ATP ModelAdenineRibose3 Phosphate groups

  • ATP- ADP CycleWhen ATP loses a phosphate group it releases energy and becomes ADP (Adenosine Diphosphate).

  • ATP vs. ADP compared to a batteryADPATPAdenosine diphosphate (ADP) + Phosphate Adenosine triphosphate (ATP)PartiallychargedbatteryFullychargedbattery

  • ATP-ADP Cycle

  • PhotosynthesisPhotosynthesis plants trap the suns energy and store it in molecules of glucose.Process of using suns energy to make food for the plant.

  • Photosynthesis FormulaProcess of Photosynthesis sunlightCarbon Dioxide + Water glucose + oxygen chlorophyll Reactants Products

  • Photosynthesis takes place in leaves (primarily)Leaves are the major sites of photosynthesis (although any green vegetation can do so).

  • Within cells of the leaf, photosynthesis takes place in the CHLOROPLASTSElodea cells with small, circular chloroplasts

  • Thought it didnt go any smaller?

  • Within those crazy chloroplastsThylakoids: sacs containing chlorophyll (pancake)Grana: stack of thylakoid disks (stack of pancakes)Stroma: the region outside the grana. (syrup)

  • So wheres the juice?Nature of SunlightLight = electromagnetic energy (radiation), travels in rhythmic waves ( wavelengths)Entire range = electromagnetic spectrumVisible light drives photosynthesis

  • Photons & PigmentsLight behaves like individual particles called photonsLight can be absorbed, reflected, transmittedThings that absorb called pigmentsPhotosynthesis pigments:chlorophyll a (blue-green)chlorophyll b (yellow-green)carotenoids (yellow-orange)

  • Two Steps of Photosynthesis:

    Light Dependent ReactionLight Independent Reaction (also called Calvin Cycle or Dark Cycle).

  • Light-Dependent Reactions- 1st step of PhotosynthesisTakes place in thylakoid membranes (pancakes).Requires light energySunlight and water enter the grana as reactants.Oxygen is produced.ATP and NADPH go to the Calvin Cycle.

  • Sunlight- reactantCarbon Dioxide- reactantOxygen- productGlucose/Sugar- productLight-Dependent ReactionsCalvinCycle NADP+ADP + PATPNADPHWater- reactant

  • 2nd Step: Light-Independent Reactions(Calvin Cycle/Dark Cycle)No light requiredTakes place in the stroma (syrup)Carbon dioxide enters as reactant.Glucose is produced.For every 6 molecules of CO2, only one molecule of glucose is formed.ADP and NADP+ go to Light Dependent Step.

  • Sunlight- reactantCarbon Dioxide- reactantOxygen- productGlucose/Sugar- productLight-Dependent ReactionsCalvinCycle NADP+ADP + PATPNADPHWater- reactant

  • Cell RespirationThe process where food molecules are broken down in the presence of oxygen to release energy.Takes place in mitochondria and cytoplasm.This process may be:Aerobic ( in the presence of oxygen)Anaerobic (without oxygen)The equation for cellular respiration is:6O2 + C6H12O6 6CO2 + 6H2O + Energy

  • 3 Main Stages of Cell RespirationGlycolysisKrebs CycleElectron Transport Chain

  • GlycolysisOccurs in cytoplasm One molecule of glucose is broken in half, producing pyruvic acids.2 molecules of ATP are producedDoes not require oxygen (anaerobic)

    2 Pyruvic acid

  • After GlycolysisIf oxygen is present ( aerobic) the second stage is the Krebs cycle.If oxygen is not present, glycolysis is followed by Fermentation.

  • Krebs Cycle (also called citric acid cycle)At end of glycolysis about 90% of the chemical energy from glucose is still unused. Oxygen needed to extract that energy.Aerobic (requires oxygen)Occurs in mitochondria.Pyruvic acid is broken down into carbon dioxide.

  • Electron Transport ChainUses high energy electrons to convert ADP to ATP 34 more ATP molecules per glucose molecule are produced in addition to the 2 ATP molecules produced during glycolysis.Water is also a product.

  • Respiration: AnOverviewGlucoseGlycolysisCytoplasmPyruvic acidElectrons carried in NADHKrebs CycleElectrons carried in NADH and FADH2Electron Transport ChainMitochondriaMitochondriaSection 9-1Go to Section:

  • FlowchartSection 9-2Glucose (C6H1206)+Oxygen (02)GlycolysisKrebs CycleElectron Transport ChainCarbon Dioxide(CO2)+Water(H2O)Go to Section:Cellular Respiration

  • FermentationReleases energy form food molecules in the absence of oxygen (anaerobic)The two main types of Fermentation are :Alcoholic fermentation Lactic Acid Feremtation

  • Alcoholic FermentationOccurs in yeasts and other microorganisms.Converts pyruvic acid to ethyl alcoholCauses bread to rise

  • Lactic Acid fermentationLactic acid is produced in your muscles during rapid exercise.Lack of oxygen to the muscles- causes muscle soreness.Pyruvic acid is converted into lactic acid

  • Chemical PathwaysGlucoseGlycolysis Krebs cycle Electron transportFermentation (without oxygen)Alcohol or lactic acidSection 9-1Go to Section:


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