Inorganic ions

• Ion

  An atom or group of atoms that has a positive or negative charge.
• cation

  A positively charged ion
• inorganic ion

  occur in solution in the cytoplasm and bodily fluid of organisms some in high concentrations and others in very low concentrations

  -one that does not contain carbon (with few exceptions )

  -ion role determines where it is found in high or low concentrations
• Hydrogen ions

  determine the pH of substances such as blood the higher the concentration of hydrogen ions the lower the ph

  Enzyme-controlled reactions are affected by ph
• iron ions in haemoglobin

  large protein that carries oxygen around the body in the rbc It is made up of four different polypeptide chains each with an iron ion fe2+ in the centre

  -it's the fe2+ that actually binds to the oxygen in haemoglobin so it's a key component

  -when oxygen is bound the fe2+ ion temporarily becomes fe3+ ion until oxygen is released
• Sodium ions

  glucose and amino acids need a bit of help crossing cell membranes a molecule of glucose or amino acid can be transported into a cell alongside sodium ions this is known as co-transport
• Phosphate Ions

  when a phosphate ion PO4^3- is attached to another molecule it's known as a phosphate group DNA RNA and ATP all contain phosphate groups it's the bonds between phosphate groups that store energy in ATP

  the phosphate groups in DNA and RNA allow nucleotides to join up to form the polynucleotides