Question

Photosynthesis Lab


Why was the cool water plunge on the leaf? (Iodine)
Why does iodine turn blue-black in the presence of starch?

Answer 1

Answer:

1. Plunging flowers up to their necks in cool water quickly reduces the temperature of stems and petals, helping to assure that they are crisp. Indeed, low temperatures are the No. 1 factor in extending a flower's life. ... Florists use warm water only for resuscitating wilted flowers, because warm water is absorbed quickly.
2. Amylose in starch is responsible for the formation of a deep blue color in the presence of iodine. The iodine molecule slips inside of the amylose coil. ... This makes a linear triiodide ion complex with is soluble that slips into the coil of the starch causing an intense blue-black color.