Demonstrating the role of hydrogen acceptors

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    Created by
    charlie rice

    Cards (9)

      1. Place 5g of chopped lettuce in a mortar with 10cm3 of buffer solution and grind with pestal
    • 2. Pour contents of the mortar through muslim to filter into beaker
    • 3. Pour the suspension into centrifuge tubes, counterbalancing the tubes
    • 4. Centrifuge at high speed for 10-12 minutes
    • 5. Pour off and sucked the supernatant of the centrifuge tubes to remove organelles smaller than chloroplasts
    • 6. The sedimented chloroplasts in the centrifuge tubes can be added to two tubes (A+B). Buffer is also added. One of these tubes with chloroplasts is covered with foil (B) to prevent light reaching the chloroplast. Tube C contains buffer
    • 7. DCPIP is added to each of the tubes and the tubes are placed in a beaker of crushed ice
    • 8. The beaker containing the tubes is placed under a very strong light source and the colour of each tube is examined every 5 minutes for 20 minutes (4 times)
    • 9. Tube A changes from blue-green to green as the chloroplasts are green, this shows that the DCPIP is reduced due to the electrons produced during the light dependent stage
      Tube B stays blue-green as the DCPIP is not reduced as the chloroplasts are not illuminated, light dependent stage does not occur