[ad_1]
Water is formed by combining hydrogen and hydroxide ions. The hydroxyl radical, a reactive form of the hydrogen-oxygen combination, is important in laboratory, commerce, medicine, and atmosphere. However, it is generally considered undesirable in the human body as it is a form of free radical associated with disease and aging. Airborne particulates and transition metal ions can lead to lung disorders and chemical attack on DNA strands.
Water is an electrically neutral molecule that can be formed through the combination of hydrogen ions and hydroxide ions, such as in acid-base reactions. Written in chemist shorthand, the reaction is H+ & OH- → H2O. Here, the lone hydrogen atom is actually an ion, which carries no negative electrons and therefore carries a positive charge, while the hydrogen-oxygen combination possesses two free electrons, which gives it a negative charge. Another form of the hydrogen-oxygen combination can be produced, which carries only one free electron, not two. This is the electrically neutral, but chemically very reactive hydroxyl radical.
Oxygen is strongly electronegative, while hydrogen is electropositive. Also, the hydrogen atom is quite small compared to the oxygen atom. It is the “electron-loving” oxygen atom, rather than the hydrogen atom, that carries the free electron. A population of free radicals decreases in number over time through friction, such as when two hydroxyl radicals combine to form a hydrogen peroxide molecule. Conversely, easily cleaved peroxides – especially organic peroxides with large appendages that tend to lengthen those bonds, such as di-tert-butyl peroxide or benzoyl peroxide – are used as sources of free radicals in laboratory and commercial syntheses. .
The hydroxyl radical is important, not only in the laboratory and commerce, but also in medicine and in our atmosphere. Tropospheric nitric oxide pollutants from automobiles and factories decompose to release excited oxygen atoms, •O. These individual atoms, not to be confused with oxygen molecules, O2, combine with the humidity in the air, converting into hydroxyl radicals, •OH. There are other sources of the hydroxyl radical, more commonly seen in other situations, including the reaction of ozone with double bonded organic compounds called alkenes. In most naturally occurring cases, hydroxyl radicals are not considered desirable; such is the case in the field of health and medicine.
This is because hydroxyl radical is a small, highly mobile form of free radical that is soluble in water. In the human body, free radicals are generally considered undesirable and can be associated with disease and aging. One enzyme system of concern is the respiratory system, where free radicals attack the body’s delicate tissues. Airborne particulates – especially transition metal ions – have been recognized as hydroxyl radical formers in moist environments such as lung tissue and lead to lung disorders, including cancer. The hydroxyl radical has also been associated with chemical attack on DNA strands.
[ad_2]