PHOTOSYNTHESIS - STARCH TEST

Question 1

How can photosynthesis be investigated?

Answer 1

Photosynthesis can be investigated to show the production of starch + importance of chlorophyll.

Question 2

How does the starch test work?

Answer 2

1. heat leaf in boiling water for 30 SECS (stops chemical reactions.
2. heat it in boiling ethanol for few minutes (remove most of its colour + makes it possible to extract chlorophyll).
3. wash with water + place onto white tile.
4. add iodine solution from dripping pipette.

Question 3

What will happen if the leaf contains starch?

Answer 3

After a few minutes, parts of leaf containing starch will turn BLUE - BLACK.

Question 4

How is ethanol heated?

Answer 4

using a hot water bath

Question 5

Why is ethanol heated in a hot water bath?

Answer 5

SAFER THAN USING A BUNSEN BURNER BECAUSE ETHANOL IS FLAMMABLE.

Boils at 78ºC so tube of it boils when placed in beaker of hot water.

Question 6

Describe 3 safety hazards for this test

Answer 6

• Wear safety goggles
• keep ethanol away from bunsen burner (its flammable)
• tie hair back