1. UNIT 2: PLANT NUTRITION
STARCH PRODUTION IN PLANTS
Objectives:
Prove starch production in green plants.
Demonstrate that starch production is related with light.
Materials
Ring, ring stand, petri dishes. Burner, forceps, scissors, test tube, beaker, clips, silver
paper.
A plant.
Chemical products: ethanol (96%), lughole.
Method
1. Same days before starting the experience cut a silver paper rectangle and fix it to
a whole leave, using clips.
2. Prepare the burner, ring and ring stand following teacher instruction.
3. Fill up the beaker with water.
4. Light the burner to heat the water.
5. Tear the leave that you fixed with silver paper and another one.
6. Boiled both in water during 2 minutes.
7. Take them out of water using forceps.
8. Put them in separated test tubes fill them up with ethanol.
9. Place both tubes in the beaker. Be careful with the ethanol because is
flammable. Keep them there for five minutes.
10. Take the leaves out using forceps and put them separately in the petri dish.
11. Use lughole to cover them.
Results
Explain the presence or absence of starch in the different leaves.
Remember that lughole turns blue-black when it reacts with starch.