Photosynthesis

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Photosynthesis
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PhotosynthesisOverview

• Defined Production of sugar oxygen from CO2,
  water, sunlight
• Endergonic reaction Requires energy
• Who Plants, algae, some bacteria
• End Result Sugar for food and oxygen (waste)
• 2 step process

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Step 1 Light Reaction

• Where Thylakoid membranes of chloroplast
• What happens?
• 1) Light energy converted into chemical energy
  (ATP)
• 2) Water (H2O) broken apart and the oxygen is
  released as a waste product
• How Chlorophyll absorbs light energy and
  electrons become excited
• Excited electrons bond ADP P to create ATP
• Sunlight energy has been converted into chemical
  energy (ATP)
• No sugar createdyet!!!

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Step 2 Dark Reaction

• Where Stroma (fluid interior) of chloroplast
• What happens? ATP (from light reaction) creates
  sugars
• How?
• ATP breaks apart CO2 H2 from water
• Atoms recombine into glucose and other sugars
• Sugar is used by plants, algae, and some bacteria
  as a food source (autotrophs)

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The Big Picture

• Reasons I love autotrophs!
• All food energy on earth can be traced back to
  photosynthesis
• Autotrophs absorb CO2
• Problem Greenhouse Effect
• The Good GHE naturally warms Earth by trapping
  heat
• The Bad CO2 from fossil fuels traps excess heat
  near Earths surface
• AKA Global Warming
• Solutions Regrow plants to absorb the extra CO2,
  reduce use of fossil fuels

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The Greenhouse Effect
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QuickReview

• CO2, Water, Sunlight are used during
  photosynthesis
• Sugar and Oxygen are created as a result of
  photosynthesis
• Photosynthetic life forms the basic of life on
  earth