Write the balanced chemical symbol equation for the synthesis of glucose via this pathway.

A student conducts an investigation to determine the spatial distribution of starch in the leaves of Pelargonium plants. The laboratory protocol is outlined below:

1. Immerse the harvested leaf in a beaker of boiling water for approximately 30 seconds.
2. Extinguish any open Bunsen burner flames in the vicinity.
3. Using forceps, transfer the leaf into a boiling tube half-filled with ethanol. Place this tube into the hot water in the beaker.
4. Once the leaf has lost its green colour, remove it and dip it into warm water for a few seconds.
5. Spread the leaf flat on a white tile and add a few drops of iodine solution.

Explain the specific chemical hazard associated with ethanol in step 3, and justify why step 2 must be executed prior to heating the ethanol.

State the biochemical and structural purposes of treating the leaf with boiling water in step 1.

Explain why the extraction of pigments with hot ethanol in step 3 is critical for obtaining an accurate visual result in step 5.

Prior to performing the starch assay described above, specific pre-treatments and setups are required to isolate individual independent variables. Describe the experimental steps a student must carry out on the plants to demonstrate the necessity of each of the following factors for starch synthesis:

light illumination

the presence of chlorophyll

an atmospheric supply of carbon dioxide