photosynthesis

• photosynthesis


  the process by which plants synthesise glucose using light energy from the sun

  light energy is converted into chemical energy
• where does photosynthesis take place

  within chloroplasts in leaf palisade cells

  they contain chlorophyll, a pigment which absorbs light energy
• is photosynthesis and endothermic or exothermic reaction

  endothermic - as energy is transferred from the environment to chloroplasts by light
• leaf adaptations which maximise the rate of photosynthesis

  • broad leaves - maximise surface area
  • thin leaves - short diffusion distance
  • air spaces - allow CO2 to enter and O2 to leave
  • guard c ells - control the opening of the stomata for gaseous exchange and prevention of water loss
• 4 main factors which affect the rate of photosynthesis

  • temperature
  • light intensity
  • carbon dioxide concentration
  • amount of chlorophyll
• a limiting factor

  an environmental factor which can restrict the rate of photosynthesis
• 5 uses of glucose produced during photosynthesis

  • respiration
  • starch for storage
  • cellulose for strength
  • protein synthesis combined with nitrates
  • lipids are stored for energy