Cations:

• Calcium ions (Ca²⁺) - Involved in muscle contraction and nerve impulse transmission

• Sodium ions (Na⁺) - Involved in co-transport, reabsorption of water in the kidney and nerves impulse transmission.

• Potassium ions (K⁺) - Involved in stomatal opening and nerve impulse transmission.

• Hydrogen ions (H⁺) - Involved in chemiosmosis, pH determination and catalysis of reactions.

• Ammonium ions (NH₄⁺ ) - Involved in nitrogen cycle, where by bacteria convert ammonium ions into nitrate ions.

Anions:

• Nitrate ions (NO₃^-)- Mineral ion absorbed by plants to provide a source of nitrogen to make amino acids.

• Hydrogencarbonate ions (HCO₃^-) - Maintains the pH of the blood.

• Chloride ions (Cl^-) - Provide a negative charge to balance to positive sodium ion and potassium ions in cells. Also acts as a cofactor for amylase.

• Phosphate ions (PO₄^3-) - Involved in the formation of phospholipids for cell membranes, nucleic acid and ATP formation and in making bones.

• Hydroxide ions (OH^-) - Involved in regulation of blood.