FA 5

• Photosynthesis


  1. Photoautotrophs

  2. Carbon dioxide + water + energy → glucose + oxygen

  3. 6 C02 + 6 H20 + energy → C6 H12 06 + 6 02

  4. Evapotranspiration: water → oxygen

  5. Energy is conserved: sun's energy → chemical energy

  6. Sugar molecules breakdown to release energy
• Photosynthesis


  • The reaction is driven by sun's energy
  • By-product oxygen is used for cellular respiration
• Leaves


  • Lower epidermis contains small openings (stomata) that regulate the release of and exchange of CO and O
  • Guard cell regulates opening and closing of each stoma
  • Palisade layer where most chloroplasts are
  • Spongy layer also has chloroplasts, and where gas exchange takes place
• Chloroplasts


  • Organelle of where photosynthesis takes place
  • Consists of inner and outer membranes
  • Thylakoid disc-like structure
  • Chlorophyll embedded in membrane and responsible for green color of plants and captures and absorbs sun's energy
  • Lumen: internal space enclosed by the membrane
  • Granum - stack of thylakoids, forms the third membrane layer
  • Stroma - liquid-filled space that surrounds the granum
• Light dependent reactions


  1. Thylakoid membranes

  2. Reactants: light energy, water

  3. Products: Oxygen, ATP, NADPH

  4. Photoactivation: chlorophyll captures light energy

  5. Photolysis: water is broken into hydrogen(H+) and oxygen(O2)

  6. Oxygen is released after photolysis

  7. An electron of water is removed and transferred to NADP+ to form NADPH. Phosphorus(Pi) is added to ADP to produce ATP.
• Light independent reactions (calvin cycle)

  1. Stroma

  2. Reactants: ATP, NADPH, Carbon dioxide

  3. Products: glucose, ADP, NADP+

  4. Energy from ATP(energy-carrier) and NADPH(electron-carrier) are used to produce glucose then they revert back to NADP+ and ADP, return to the LDR and the process will go on