Inorganic Ions

• An Ion is an Atom (or group of atoms) with an Electric Charge
• An Ion with a Positive charge is a Cation
• An Ion with a Negative charge is an Anion
• An Inorganic Ion is one that Doesn't Contain Carbon (mostly!)

We need to know about 5 cations and 5 anions:

Name of Ion	Chemical Symbol	Examples of roles in biological processes.
Calcium	Ca2+	The Transmission of Nerve Impulses and the Release of Insulin from the pancreas. It acts as a Cofactor for many enzymes. Also important in Bone formation
Sodium	Na+	For Generating Nerve Impulses for Muscle Contraction and for Regulating Fluid Balance in the body.
Potassium	K+	Generating Nerve Impulses, for Muscle Contraction and Regulating Fluid Balance. It activates Enzymes needed for Photosynthesis in plants
Hydrogen	H+	Affects the pH of Substances  if the amount of H+ is greater than the amount of OH- then it is an acid, vice versa is an alkali. Also Important for Photosynthesis Reactions in the thylakoid membranes inside chloroplasts
Ammonium	NH4+	Absorbed from the Soil by the plants and is an important Source of Nitrogen (used to make amino acids and nucleic acids)
Nitrate	NO3-	Exactly the same as NH4+
Hydrogencarbonate	HCO3-	Acts as a Buffer to help maintain the pH of the Blood
Chloride	Cl-	Involved in the 'Chloride Shift' which helps to Maintain pH of the Blood during Gas Exchange. Acts as a Cofactor for Amylase (an enzyme). Also involved in some Nerve Impulses
Phosphate	PO43-	Involved in Photosynthesis and Respiration Reactions. It is needed for the Synthesis of many Biological Molecules such as Nucleotides including ATP, Phospholipids and Calcium Phosphate (strengthens bones)
Hydroxide	OH-	Affects the pH of Substances (see H+)