Chemical And Biological Effects
Free radical reactions are useful in certain beneficial chemical processes, such as those used in the production of rubber and plastics. In these processes the free radicals react quickly to form long chains of chemicals known as polymers. However, in biological systems these reactions can cause harm. For example, radicals known as superoxides are formed when oxygen molecules are split apart. While these radicals can participate in the destruction of invading organisms by white blood cells, they can injure or kill cells when natural enzyme controls fail. Unchecked they can attack lipids, proteins, and nucleic acids. Therefore, free radicals in the body can contribute to cancer, heart attacks, strokes, and emphysema and may even play a role in arthritis and Alzheimer disease.