Photosynthesis

• Photosynthesis

  The process where plants make their own food
• Photosynthesis is a reaction which converts what energy to another energy?

  Light energy --> Chemical energy
• The word equation for photosynthesis is

  Carbon dioxide + water --------> Sugar + Oxygen

  (Light energy)
• What are the reactants of photosynthesis?

  Carbon dioxide + water
• What are the products of photosynthesis?

  Sugar + Oxygen
• What are the three essential requirements for photosynthesis?

  Sunlight, heat/warmth and chlorophyll
• There are two stages of photosynthesis:

  Light reactions and carbon fixation
• Light reactions

  • Light energy from the sun is trapped in the chlorophyll in the chloroplasts and is converted into chemical energy
  • Water is split into hydrogen and oxygen
  • Oxygen diffuses out of the cell and is released into the atmosphere
• The word equation for stage 1 is:

  Water + energy absorbed ------> Hydrogen + Oxygen

  by chlorophyll
• Carbon fixation

  • This process is a series of enzyme controlled reactions
  • Hydrogen and ATP which was made in the first stage of photosynthesis combines with carbon dioxide to form glucose
  • This stage requires energy which is supplied by ATP
• The word equation for stage 2 is:

  (Enzymes)

  Hydrogen + carbon dioxide ------------> Sugar

  (Stage 1) (ATP- Stage 1)
• The fate of sugar:

  • Respiration to provide energy for cells
  • Starch is a storage carbohydrate made from glucose molecules which are linked together
  • Cellulose for structure which forms part of the plant cell wall
• Limiting factor

  Is any factor which limits the rate of photosynthesis when it is in short of supply
• What are the limiting factors of photosynthesis?

  • Light intensitycarbon dioxide concentration, and temperature.