Cell Energy  Why do cells need energy?  How can cells store energy?  A molecule called adenosine triphosphate  ATP Energy is stored in ________________.

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  • Cell EnergyWhy do cells need energy? How can cells store energy?A molecule called adenosine triphosphateATP

    Energy is stored in ________________Chemical Bonds

  • Cell EnergyWhy does ATP have so much stored energy?

    ATP can be recycled.

  • Why worry about Photosynthesis?Food chains begin with the SUN!Autotrophs are the first level of the food pyramid.Heterotrophs eat autotrophs

    Carbon sinks atmosphere

  • What is Photosynthesis?Process used by autotrophs to change the suns energy into chemical energy stored in organic molecules.Trapping energy from sunlight and using it to build food (complex carbohydrates)Plants, protists (algae), bacteria

  • Pigments and Wavelength of Light

  • Equation for Photosynthesis6 CO2 + 6 H2O + sunlight Glucose + 6 O2

  • The Chloroplast- Where Photosynthesis HappensThe insides of leaf cells can contain a half million chloroplasts per square mm of leaf surfaceSTROMA



  • Photosynthesis has:Light Reactions take place in the GRANA where electrons (e-) are excited by the suns energy and through the splitting of H2O Dark Reactionstake place in the STROMA and are where the glucose is made.

  • The Light Reactionslight energy converted to chemical energy (ATP and NADPH)Location: Thylakoid membranes of grana inside chloroplastReactants- Sunlight + waterProducts- ATP, O2 , H


  • TheThe Light ReactionsGRANACHLOROPLAST

  • The Light Reactions: Photolysis Sunlight excites an electron and water is split. O2 is released into atmosphere

    ATP is made as electron falls down the Electron Transport Chain

    Excited electron produces NADPH.

    Both ATP and NADPH will take go to the DARK SIDE.

  • The Light Reactions


    Welcometo the DARK sideCalvin Cycle


    Calvin Cycle Produces complex carbs ( glucose, startch, cellulose)Happens in stromaReactants: CO2 (from atmosphere)ATP (from light reactions) Hydrogen (from NADPH)Product: Glucose! Sugar! FOOD!

  • Dark Reactions(Inside chloroplast not in grana)

    CO2 enters the cell from the air.CO2 combines with Hydrogen from the light reactions to form carbohydrates (like sugar and starch)

  • The Calvin Cycle

  • Photosynthesis EssayHave you ever heard that the chloroplasts produce glucose? This is how they work. It starts with sunlight hitting the chloroplast. The energy of the sunlight is captured by chlorophyll. This energy is used to split water into hydrogen and oxygen. The oxygen is released. This process is called the light reaction. The hydrogen is used in the dark reactions. Carbon dioxide combines with the hydrogen through a series of reactions called the Calvin Cycle which makes glucose. This process is photosynthesis.

    Transport materials in and out of the cell, movement, building proteins

    *Because the bonds are hard to maintain because phosphate is charged and doesnt want to touch

    ATP can be recycled: a phosphate group is added to ADP, forms ATP, then ATP used one phosphate, so we add another one.*********Without the light reactions, the Calvin Cycle would not have the Hydrogen and ATP to begin! *ATP from light reaction and Hydrogen (in NADPH)*****


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