Inorganic Ions

• IONS IN LIVING ORGANISMS:

  • Ions are gained through nutrition. 
  • The cytoplasm & body fluids maintain optimum level of each ion, depending on the function of the cell.
  • This means some ions are found in high concentrations while others would be toxic if concentrations were allowed to increase.
• HYDROGEN IONS:

  • Hydrogen ions= protons
  • pH values: concentration of hydrogen in a solution. pH is important in enzymes and respiration
  • Mitochondria accumulate hydrogen in the intermembrane space to allow aerobic respiration
• IRON IONS:

  • Iron ions are the central part of the haem group in haemoglobin allowing red blood cells to transport oxygen and carbon dioxide
• ZINC IONS:

  • Need to be present for carbonic anhydrase to function
  • Carbonic anhydrase: zinc containing enzyme that catalyses the reversible hydration of carbon dioxide (conversion of carbon dioxide to carbonic acid & back again)
  • Carbonic anhydrase can help with carbon dioxide transport in blood and formation of hydrochloric acid in the stomach
• POTASSIUM IONS:

  • Involved in the conduction of nerve impulses
  • Involved in co-transport of sodium as protein channels (sodium-potassium pumps) are across the cell membranes that use ATP to move sodium ions out the cell for potassium ions that move in
• SODIUM IONS:

  • Transport of sodium ions across the cell membrane of cells in the intestine allows the co transport of glucose and amino acids
  • Glucose or amino acids are drawn into cells along with sodium ions that have been actively transported out by the sodium-potassium pump
• PHOSPHATE IONS:

  • Phosphate ions are an essential part of the sugar phosphate backbone of DNA molecules (makes important phosphodiester bonds in DNA)
  • Adenosine triphosphate (ATP) can form ADP and release a phosphate ion along with energy
  • ADP can also store energy by gaining a phosphate ion & taking in energy
  • ATP is the universal energy currency of living organisms