The best way to fully comprehend what free radicals are is to look at them from a cellular level. Here's a quick Physiology 101 lesson: The human body is made up of various kinds of cells.
Cells are composed of many different types of molecules. Molecules consist of one or more atoms of one or more elements joined by chemical bonds.
Atoms are made up of a nucleus, protons, electrons, and neutrons. The number positively charged particles (protons) in the nucleus of the atom is what determines how many negatively charged particles (electron) will surround the atom.
Electrons are take care of the chemical reactions and are the substance that bonds atoms together to form molecules. Electrons surround, or "orbit" an atom in one or more shells.
When two electrons are present, the innermost shell is full. When the firat shell is completely occupied, the electrons begin to fill the second shell and son..
The single most important feature in determining the chemical behavior of an atom is how many electrons are contained in the outer shell.
An atom that has a full outer shell does not enter in chemical reactions. Atoms seek to reach a state of maximum stability by one of the following:
Gaining or losing electrons to either fill or empty its outer shell
Share electrons with other atoms to complete the outer shell
The most common way atoms complete their outer shell is by sharing electrons with other atoms. This bonding share strategy used by atoms satisfies the stipulations needed for maximum stability of the molecule.
Normally, bonds wont split in a way that leaves a molecule with an odd, unpaired electron. But when weak bonds split, free radicals are formed--free radicals are very unstable and react quickly with other compounds, trying to capture the needed electron to gain stability.
Free radicals usually attack the closest molecule they cam find. From here they radicals begin the process of stealing electrons from the molecule which ends in the molecule becoming a free radical itself. This process brings into being a cascading effect where the conclusion leaves a living cell being disrupted.
Some free radicals usually occur during metabolism;at times the body's immune systems cells will even purposefully create them to neutralize viruses and bacteria. However, environmental factors such as pollution, radiation, cigarette smoke and herbicides can also spawn free radicals.
The body usually defends these free radicals well, however when antioxidants are not available or free radical damage becomes too excessive, cell damage can occur. The most significant importance to this free radical damage is that it accelerates the aging process in humans