What do most people think about when they hear the word oxygen? Maybe they think about trees, nature, and air. They’d be right to think about the air being represented by oxygen, in fact that is why the sky is blue, but to think that oxygen is a “good” healthy and clean gas is not a very accurate perspective.
Oxygen is the most common element in the Earth’s crust, and the second most common element in the Earth’s atmosphere.
Oxygen is responsible for the first major extinction, known as the Oxygen Holocaust. It was an event that killed off hundreds, even thousands of species of microorganisms that were the first life on Earth. Each species with its own potential at evolving into a more complex organism. The Oxygen level had been a mere 3%, but it was still quite potent.
So, why was oxygen so fatal?
Many of these early photosynthesizers used the abundant carbon dioxide, and sunlight to create energy. They had never previously encountered any significant amounts of oxygen, and to them it was a toxic gas.
Oxygen is used by most organisms, with exceptions including plants and the simplest microorganisms, both of which were the first inhabitants of Earth. If the oxygen levels in the room you are in right now were significantly higher, you might just burst into flames with the first step you take. Not so angelic anymore now is it? Oxygen can be a really nasty chemical if you aren’t careful.
So what does oxygen mean to us today? Oxygen accounts for about 20% of the atmosphere and is found in the form of O3 in the ozone layer. Oxygen is used in our respiratory system, and it transitions between our cells and tissues almost constantly.
Oxygen is an element that follows the octet rule, meaning that it likes to have 8 valence electrons, but oxygen only has 6 electrons, which is why it reacts with iron, calcium, sodium, aluminum, magnesium, and a couple thousand other elements.
However, sometimes rogue and nasty oxygen comes out of this reaction. This is called a Free Radical. When a Free Radical enters our body, it will bond with practically anything! Remember how oxygen is constantly moving through our body? This free radical oxygen might bond with our cells, our DNA, proteins and our tissues. This can cause some types of cancer, mutations, and malfunctions in your body.Scientifically, this is the same thing as being rusted from the inside out.
This constant cell damage is called Oxidative Stress. Some scientists believe that this is one of the causes behind old age.
However, free radicals are like nuclear power, they are both dangerous, and work to our benefit. Free radicals are used as a weapon by some of our white-blood cells, and evidence suggests that free radicals are used in brain and nerve signaling between cells. Our body realizes both sides of the free radical, and try to keep the damage it does to a minimum. When a cell realizes it has a free radical, it tells the body and the other cells to kill it (the cell with the free radical) for “the greater good.” This paired with antioxidants, which prevent the oxidation damage of free radicals, make a powerful protection against free radical damage.
Oxygen can be very dangerous, but it is also an essential part of our daily existence. We just cannot live without it. Although personally, I would not try.