Wednesday, August 12, 2009

How Free Radicals Work

By Dr. Lorna Mistranski

To understand the way that free radicals and antioxidants interact, you must first understand a bit about cells and molecules. This is a quick course in Physiology/Chemistry lesson: The human body is composed of many different types 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 responsible for the chemical reactions that take place inside the atom as well as the substance that holds the atom together to form molecules. Electrons orbit the 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.

A compound that has a full outer shell usually does not enter in chemical reactions. Atoms look to reach a point of maximum stability by one of the following:

Loose or pick up electrons to either empty or fill the outer shell

Share electrons with other atoms to complete the outer shell

Atoms regularly complete their outer shells by sharing electrons with other atoms. Sharing electrons allows the atoms that are bound together to satisfy the conditions of maximum stability for the molecule.

Usually when a split occurs, it never leaves the molecule with an odd, unpaired set of electrons. However, when bond does split, free radicals are created--they tend to move and react quickly to other compounds as they begin to attempt to capture as many electrons as they can to achieve maximum stability.

The most common way free radicals attack is by finding the closest molecule that is stable and from there they begin the process of stealing electrons. When the molecule that is attacked starts losing the electrons, it becomes a free radical as well. When this process begins, it creates a chain reaction in which the end result is a disruption of a living cell.

Free radicals will frequently arrive during metabolism and sometimes the body will even produce them to fight off viruses and bacteria. Free radicals also come from pollution such as radiation, cigarette smoke, and pesticides.

Typically, the body is able to handle free radicals, but if antioxidants are unavailable, or if the free-radical production becomes excessive, damage can occur. Most importantly is that free radical damage accumulates with age.

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