Inorganic ions are EVERYWHERE. ALL OF THEM EVERYWHERE. They’re up in your cytoplasm and all up in your tissue fluid and some of them are like super high in concentration like sodium and potassium while others are like uber low otherwise u dead. We talkin about hydrogen ions that determine pH which is the acidity or alkalinity of e.g. your blood. This is key to basically all the proteins circulating and all the cell reactions and everything.
Haemoglobin which is a good friend circling oxygen round the bod for max performance and non-dead status has iron ions at its core to actually bind the oxygen. Apparently we have an inch of an iron nail’s worth of iron in our body? BOO YAH IT’S ‘APPENIN.