We should be grateful for snot, the nasal mucous that works overtime to combat the nasty bugs we inhale when we breathe. What causes it to be green is an enzyme, myeloperoxidase, which actually makes bleach to kill microbial invaders. This tiny bleach factory is safely (for us) contained in a special kind of white blood cell called a neutrophil, which is a particularly active part of our immune system that hunts down and swallows up invasive cells.
Researchers in Germany have captured some fantastic (and terrifying) videos of a neutrophil mercilessly stalking the bad guys, before engulfing them whole – these cells are truly voracious. You do not want to make an enemy of a neutrophil. It will find you, and it will kill you.
Once captured, the neutrophil proceeds to douse its captives with bleach manufactured by our recent acquaintance, myeloperoxidase. Doing this internally allows a degree of damage limitation, tantamount to a controlled explosion. Sadly though, much like Monty Python’s Mr Creosote, the neutrophils can’t keep consuming forever. Eventually they take a suicidal step, rupturing open and spewing their digested contents out into the warzone, ready for you to honk out of your nose and admire.
Even though green snot may be disgusting at times, it could be worse. The chemical explanation of snot at Infectious Enthusiasm links the operant molecule, haem, to the red in our red blood cells. Just imagine how horrible it would be to blow your nose and see red come out! -via Not Exactly Rocket Science
(Image credit: Flickr user tanjila ahmed)