photosynthesis

• what is the word equation for photosynthesis?

  carbon dioxide + water ----> glucose + oxygen
• to produce glucose molecules by photosynthesis, energy is required as it is endothermic (takes heat in)
• where does the energy come from that is needed for photosynthesis?


  Sunlight
• how is sunlight trapped?

  chlorophyll (found in chloroplasts)
• name the 4 limiting factors for photosynthesis?

  1. temperature
  2. CO2 concentration
  3. light intensity
  4. chlorophyll concentration
• why is temperature a limiting factor?

  1. as the temp increases, so does the rate of photosynthesis
  2. more energy is provided for the reaction
• why is CO2 concentration a limiting factor?

  as the concentration of CO2 increases, so does the rate of photosynthesis as CO2 is needed in the reaction

  after reaching a certain point, an increase in CO2 has no further effect
• why is light intensity a limiting factor?

  as light intensity increases so does the rate of photosynthesis as more energy is provided for the reaction
• greenhouses can be used to increase the rate of photosynthesis

  by controlling lighting, temperature and CO2, farmers can increase the growth rate of their crops
• the glucose produced in photosynthesis may be used by the plant during respiration to provide energy
• glucose can be changed into other products such as:

  • insoluble starch (stored in the stem, leaves or roots)
  • fat or oil (stored in seeds)
  • cellulose- to strengthen cell walls
  • amino acids to produce proteins for growth and enzymes
• to produce proteins from glucose, plants also.use nitrate ions, which are absorbed from the soil
• nitrate ions are needed to make proteins as amino acids contain nitrogen but glucose doesnt