Oxygen is essential to life, but the paradox is that the living things could not have evolved in the presence of atmospheric oxygen.  The early atmosphere contained no oxygen.  Cyanobacteria appeared around 2.7bn years ago by which time living bacteria could manage oxygen’s powerful destructive force.  Complex life forms emerged that could control the energy released by oxygen and turn it into biochemical power.  Mitochondria (bacteria engulfed into the emerging nucleated cells) provided internal energy using oxygen and were essential to the development of modern life.

The discovery of oxygen was tortuous.  Joseph Priestley first isolated ‘dephlogisticated air’ and showed the relationship between oxygen, plants and animals.  Antoine Lavoisier, using sophisticated equipment, showed that burning was the result of oxygen combining with various substances.  Respiration was internal burning.  He has been called the Father of Modern Chemistry.

Written by Mike James, Emeritus Professor, UCT