Question

Surya used a plant with variegated leaves for an experiment on photosynthesis. He tested a leaf with iodine after keeping the plant in sunlight for a few hours.

1. Which parts of the leaf will turn blue-black after the iodine test?
2. What does this tell us about the role of chlorophyll in photosynthesis?
3. Write the overall chemical equation for photosynthesis.

Answer 1

1. The green parts of the variegated leaf will turn blue-black because they contain chlorophyll and can produce starch.
2.  It shows that chlorophyll is essential for photosynthesis because only the parts with chlorophyll produce starch (which turns blue-black with iodine).
3. \[\ce{6CO2 + 12H2O ->[light energy][chlorophyll] C6H12O6 + 6H2O + 6O2 ^}\]