Photosynthesis

• Photosynthesis uses energy to change carbon dioxide and water into glucose and oxygen
• Photosynthesis takes place in chloroplasts in green plant cells, because they contain pigments like chlorophyll that absorb light
• Energy is transferred to the chloroplasts from the environment by light, making it an endothermic reaction
• Photosynthesis word equation

  carbon dioxide + water -> glucose + oxygen
• Photosynthesis (balanced) symbol equation

  6CO2 + 6H2O -> C6H12O6 + 6O2
• Plants use glucose in 5 main ways:

  • for respiration
  • making cellulose
  • making amino acids
  • stored as oils or fats
  • stored as starch
• Glucose for respiration

  Respiration transfers energy from glucose which enables the plants to convert the rest of the glucose into various other useful substances
• Glucose for making cellulose

  glucose is converted into cellulose for making strong plant cell walls
• Glucose for making amino acids

  glucose is combined with nitrate ions (absorbed from the soil) to make amino acids, which are then made into proteins
• Glucose stored as oils and fats

  glucose is turned into lipids for storing in seeds
• Glucose stored as starch

  glucose is turned into starch and stored in roots, stems and leaves, ready for use when photosynthesis isn't happening, like in the winter.
• Starch is insoluble, which makes it better for storing than glucose, because a cell with lots of glucose in would draw in loads of water and swell up