Inorganic Ions

• An ion is an atom that has an electric charge.
• An inorganic ion is an ion that doesn't contain carbon.
• Inorganic ions occur in solution, in the cytoplasm of cells, and in the body fluids of organisms.
• Each ion has a specific role, depending on its properties. An ion's role determines whether it is found in high or low concentrations.
• Hydrogen ions (H+):

  • the concentration of H+ ions determines pH of the environment
  • the more H+ ions, the lower the pH (the more acidic the environment)
  • pH affects all enzyme-controlled reactions
• Iron ions (Fe2+/Fe3+):

  • haemoglobin is made up of 4 different polypeptide chains, each with an Fe2+ ion in the centre
  • the Fe2+ ion binds to oxygen, then becomes an Fe3+ ion until oxygen is released
• Sodium ions (Na+):

  • use in the co-transport of glucose and amino acids
• Phosphate ion (PO4 3-):

  • component of ATP, DNA and RNA
  • the bonds between phosphate groups store energy in ATP
  • the phosphate groups in DNA and RNA allow nucleotides to join up to form polynucleotides