Ion Channels: Structure and Function. Ion channels are membrane protein complexes and their function is to facilitate the diffusion of ions across biological membranes. Membranes, or phospholipid bilayers, build a hydrophobic, low dielectric barrier to hydrophilic and charged molecules. They are electrical insulators.
The inert gas xenon (chemical symbol Xe) has an atomic number of 54, and it has 54 protons in its nucleus. The number of neutrons varies, however.
The number of protons determines the element, but the number of neutrons in the atom of any one element can vary. Each variation is an isotope. At least 18 radioactive isotopes of xenon are known also.