Minerals in the Body

• Once they have been ingested, minerals become dissolved in body fluids. In this form, they are called "salts." Because of their ionic composition these salts can have a positive or a negative electrical charge, which requires that they enter a cell through facilitated or active transport.
  
  

Facilitated Transport

• Facilitated transport occurs when minerals move from one side of a cell's membrane to the other through molecules that act as channels. The structure of these channels determines which minerals can pass through them.
  
  

Active Transport

• The active transport of minerals into a cell is different from facilitated transport in that it requires energy. The energy is needed to power the ion pumps in the cell's membrane, which move minerals into a cell at the same time as they move another molecule out of the cell.