Sources of Energy All living things need energy All cells need energy to carry out their functions.

  • Published on
    16-Jan-2016

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  • Sources of Energy All living things need energy All cells need energy to carry out their functions

  • PhotosynthesisPhoto (light) + synthesis (putting together)Process by which a cell captures energy in sunlight to make foodLiving things can obtain energy either directly or indirectly from the energy of sunlight captured during photosynthesis

  • OrganismsautotrophOrganism that makes its own food (uses sunlight directly)Plants, some bacteria

    heterotrophOrganism that cannot make its own food (uses sunlight indirectly)Animals that eat plants or other animals

  • Photosynthesis is a complex process that takes two stages:Stage 1:Capturing the Suns energyStage 2:Producing sugars

  • Stage 1Chloroplasts in the leaves capture energy from sunlightThe main pigment in chloroplasts is chlorophyll (a colored chemical compound that absorbs light)

  • Stage 2Need water (H2O) and carbon dioxide (CO2)water soil roots stem leavescarbon dioxide (gas in the air) enters from stomata (small openings on back side of leaf)

  • Inside the chloroplasts, the H2O and CO2 undergo a complex series of chemical reactions:PRODUCTS: sugar with 6 carbon atoms (C6H12O6), a type of carbohydrate which fuels cells oxygen (O2) which exits the leaf through the stomata *Almost all the oxygen in Earths atmosphere was produced by living things through photosynthesis

  • Photosynthesis Equation:6 CO2 + 6 H2O C6H12O6 + 6 O2 raw materials products

    = yields (or gives)Light energy

  • Uses for sugar? Some is used for food Can be converted into other compounds (such as cellulose) Some stored in plant for later use

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