Year 7 test a leaf for starch

It is important, when studying photosynthesis, to see if leaves make starch. This is the experiment we do to test this.

First boil the leaf to kill it and remove the waterproof waxy layer

Then we take out the leaf

And put it into a boiling tube with some ethanol

The ethanol has a low boiling point and is flammable so we have the Bunsen burner turned off.

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Then the leaf was washed in the hot water as it became brittle in the ethanol

Finally the leaf was spread out on a Petri dish and iodine was added to it..

If the leaf turns black it has starch in it.

Our leaves went very black.

IRP