photosynthesis

• 1. photosynthesis uses energy to change carbon dioxide and water into glucose and oxygen
  2. it takes place in chloroplasts
  3. energy is transferred to the chloroplasts from the environment from light
  4. photosynthesis is endothermic - energy is transferred from the environment in the process
• photosynthesis word equation

  $carbon\ dioxide\ +$$\ water\ \rightarrow\ glu\cos e\ +$$\ oxygen$
• photosynthesis symbol equation

  $6CO_2\ +$$\ 6H_2O\ \rightarrow\ C_6H_{12}O_6\ +$$\ 6O_2$
• factors affecting rate of photosynthesis

  • at night = lack of light
  • winter = cold temperature
  • warm/bright = lack of CO2
• 1. light provides energy needed for photosynthesis
  2. light level increase = photosynthesis rate increase but only up to a certain point
  3. beyond that, won’t make any difference - light intensity increases = rate no longer increases. either temperature or CO2 level now the limiting factor
• 1. the amount of CO2 will only increase the rate of photosynthesis to a certain point
  2. as CO2 increases = rate no longer increases. CO2 no longer limiting factor
  3. if light and CO2 are in plentiful supply then the factor limiting photosynthesis must be temperature
• 1. if temperature is limiting factor it’s too low. the enzymes work slower
  2. if plant gets too hot, the enzymes will be damaged
  3. happens at about 45°C