Photosynthesis

• Photosynthesis


  Plants produce glucose from carbon dioxide and water, using light energy
• Word equation for photosynthesis

  Carbon dioxide + water → glucose + oxygen
• Carbon dioxide


  • Comes from the air
• Water


  • Comes from the soil and moves up the stem towards the leaf
• Light energy


  • Comes from the sun
• Glucose


  Used by the plant for other organic molecules
• Oxygen


  • Given back to the air in the surroundings as a waste product
• Organs of the plant


  • Roots
  • Stems
  • Leaves
• Leaves


  • Main organ for photosynthesis in plants
  • Contain chloroplasts which contains a green pigment called chlorophyll which helps trap light for photosynthesis
• Flower


  • Main reproductive organ found in plants
• Stem


  • Supports the leaves, and contains tissue such as the xylem and phloem
• Uses of glucose by plants


  • Respiration to release energy
  • Turned into starch (stored in leaves, leaves or roots)
  • Turned into fat or oil (stored e.g. in seeds)
  • Turned into cellulose (strengthens cell walls)
  • Turned into proteins (needed for growth)
• Starch

  • A store of energy
  • The Starch molecules are insoluble very large, so they cannot move out of the plant cell
• Fat or oil


  For context – sunflower oil is obtained from sunflower seeds