Oxygen Info

Air to breathe - Air to live !

Oxygen is an integral part of breathing. It is a mandatory component to life evolution on our planet.

Oxygen and the air

Air is made of appx. 21 % oxygen. The rest is mainly made of Nitrogen (78 %) and rare gases (appx.1 %). Oxygen is the key component necessary to developing life.

Oxygen as a drug

Use of oxygen as a drug goes well back into history.

Medical oxygen is used today when a drop in oxygen is noted under certain conditions (hypoxia, hypoxemia). Hyper bar oxygen therapy, which consists in breathing oxygen in a pressurised room, allows to noticeably increase blood oxygen transport capacity. Pure medical oxygen, but also oxygen blended with narcotic gases, is also used in anaesthesia.

Properties

Elemental oxygen is a colourless, odourless, tasteless gas. It condenses into a colourless liquid at a temperature of -182.97°C. When in thick layers, oxygen shows a bluish coloration. Below -218.75°C oxygen turns solid by forming blue crystals.

Biological importance

In nature, oxygen keeps in a permanent cycle. It comes constantly from autrophobic organisms, such as cyanobacteria (blue algae), algae and plants, through oxygenated photosynthesis during water photolysis. It is the final result of that chemical reaction which frees it into the environment.

Cyanobacteria were most probably the first organisms to grow atmosphere with molecular oxygen, a residual product of their metabolism. Before, our planet had an anaerobic atmosphere. Most heterotrophic organisms, i.e. all eukaryotes animal cells, including those of man and of many bacteria, as a matter of fact use that oxygen as a source of energy. It is consequently, within the respiratory cycle, again turned into water.

Because the high reactivity of oxygen can destroy cellular structures, organisms benefit from protective enzymes such as catalase and peroxidase.
Oxygen is toxic to those organisms which don't have such enzymes. During oxygen decomposition some active oxygen derivate are generated, such as free radicals, which also can destroy a biological molecule. If they are not removed quickly enough, an "oxidative stress" appears, known to be responsible for early ageing process.

In the immunity system phagocytes (cell eaters), active derivate of oxygen (hydrogen peroxide and hyperoxide ions), in addition to other enzymes, have a function to destroy absorbed pathogenic agents.