Breaking down potassium iodide to elemental iodine.

Ok today I go by my friend the chemistry professor lab, he teaches at the local university. He is going to show me how to make elemental iodine, from iodide. He first takes 2grams of potassium Iodide salt, places it in a test tube, then ads some water, then adds some muratic acid, then about five times as much hydrogen peroxide as he has acid. He swirls it around and presto, catches in a paper funnel 1 gram of elemental iodine.
So if half of the potassium Iodide is really elemental iodine, why are we using lugols, making it etc? He then tells me it is I one, not I three, since being seperated. When mixed it captures two protons and two electrons when it blends with iodide.
Unfortunately he does not know if the body during digestion, can break it down that way into two components.
I have a background in nutrition, and I know the body releases HCL, a stronger form of muratic acid in the stomach to digest/break down proteins. Step one, but have no clue where the second and final step, hydrogen perioxide may come from to break it down in the body, I suppose one could drink some HP to finish out the steps, but for certain it would cause some oxygen rich gasses as well.
Any thoughts appreciated, trying to learn, prolly think I know more than I really do.
david lubbock tx.