Question

Why is tincture iodine used protect wound from germs?

Answer 1

Tincture iodine is used to protect the wound from germs because they are natural insecticides.

The microbiocidal action of Iodine is due to the active form, $I_2$, which is polarized by water and like all halogens (chlorine, fluorine, bromine, etc.), acts as an extremely potent oxidizer.

Activated iodine ($I_2$) reacts in electrophilic reactions with enzymes of the respiratory chain as well as with amino acids located in the cell membrane and cell wall proteins.

The well-balanced tertiary structure necessary for maintaining the respiratory chain as well as cell integrity is destroyed and the microorganism is irreversibly damaged.