How to test a leaf for starch

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  • Created by: Katy **
  • Created on: 31-12-13 09:31
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  • Test leaf for starch
    • Step 1.
      • 'destarch' plant
      • place in dark
        • 24-48 hours
    • Step 2.
      • place leaf in boiling water
        • 5 mins
        • destroys cell wall & membrane
        • this will let ethanol & iodine in & chlorophyll out of the leaf
    • Step 5.
      • few drop of orange iodine
        • leaf turns blue-black
          • starch present
    • Step 3.
      • put leaf in warm ethanol
        • ethanol dissolves fat solvent molecules (chlorophyll)
    • Step 4.
      • extract all chlorophyll ? leaf turned white
        • easier to see iodine colour change
    • Safety
      • turn off budsen burners
        • ethanol = flammable

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