Inorganic Ions

Free Inorganic Ions revision notes for OCR A Level Biology – covering specification point 2.1.2(p).


Inorganic Ions

Inorganic ions are essential to the maintenance of physical structures and physiological mechanisms in organisms. A lack of an inorganic ion can result in deficiency symptoms or diseases.

Positive ions are called cations, and negative ions are called anions.

The table below lists the common cations:

Name Symbol
Calcium Ca²⁺
Sodium Na⁺
Potassium K⁺
Hydrogen H⁺
Ammonium NH₄⁺

The table below lists the common anions:

Name Symbol
Nitrate NO₃⁻
Hydrogencarbonate HCO₃⁻
Chloride Cl⁻
Phosphate PO₄³⁻
Hydroxide OH⁻

These inorganic ions will appear throughout the biological processes studied throughout the AS and A level course. You are expected to recognise and recall their symbols.

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