Uses Of Free Radicals

Free radicals are the products of normal cellular metabolism. A free radical can be defined as an atom or molecule containing one or more unpaired electrons in a valence shell or outer orbit and is capable of independent existence. The odd number of electron(s) of a free radical makes it unstable, short-lived, and highly reactive. Because of their high reactivity, they can abstract electrons from other compounds to attain stability.

Free radicals are highly reactive and unstable molecules that are produced in the body naturally as a by-product of normal metabolism, or by exposure to toxins in the environment such as tobacco smoke and ultraviolet light. Free radicals have a lifespan of only a fraction of a second, but during that time can damage DNA, sometimes resulting in mutations that can lead to various diseases, including heart disease and cancer. Antioxidants in the foods we eat can neutralize the unstable molecules, reducing the risk of damage. The free radicals are produced during ATP through mitochondria. They are generally divided into two well-known entities reactive oxygen species and reactive nitrogen species.

What Are Free Radicals?

Chemical species having one or more unpaired electrons are called free radicals. Homolytic bond fission leads to the formation of free radicals. The free radicals are odd electron molecules and are highly reactive. Free radicals are paramagnetic in that they possess a small permanent magnetic moment due to the presence of unpaired electrons. This property is used for the detection of the presence of free radicals.

Atoms are surrounded by electrons that orbit the atom in layers called shells. Each shell needs to be filled with a set number of electrons. When a shell is full; electrons begin filling the next shell. If an atom has an outer shell that is not full, it may bond with another atom, using the electrons to complete its outer shell. These types of atoms are known as free radicals.

Atoms with a full outer shell are stable, but free radicals are unstable and to make up the number of electrons in their outer shell, they react quickly with other substances. When oxygen molecules split into single atoms that have unpaired electrons, they become unstable free radicals that seek other atoms or molecules to bond to. If this continues to happen, it begins a process called oxidative stress.

Oxidative stress can damage the body’s cells, leading to a range of diseases and causing symptoms of aging, such as wrinkles.

Production Of Free Radicals In The Human Body

Free radicals and other ROS are derived either from normal essential metabolic processes in the human body or from external sources such as exposure to X-rays, ozone, cigarette smoking, air pollutants, and industrial chemicals. Free radical formation occurs continuously in the cells as a consequence of both enzymatic and nonenzymatic reactions. Enzymatic reactions, which serve as a source of free radicals, include those involved in the respiratory chain, phagocytosis, prostaglandin synthesis, and the cytochrome P-450 system. Free radicals can also be formed in nonenzymatic reactions of oxygen with organic compounds as well as those initiated by ionizing reactions.

Effects Of Free Radicals On The Body

Oxidative Stress

The effects of oxidative stress vary and are not always harmful. For example, oxidative stress that results from physical activity may have beneficial, regulatory effects on the body.

Exercise increases free radical formation, which can cause temporary oxidative stress in the muscles. However, the free radicals formed during physical activity regulate tissue growth and stimulate the production of antioxidants.

However, long-term oxidative stress damages the body’s cells, proteins, and DNA. This can contribute to aging and may play an important role in the development of a range of conditions.

Factors that may increase a person’s risk of long-term oxidative stress include

• Obesity
• diets high in fat, sugar, and processed foods
• exposure to radiation
• smoking cigarettes or other tobacco products
• alcohol consumption
• certain medications
• pollution
• exposure to pesticides or industrial chemicals

Uses Of Free Radicals

A balance between free radicals and antioxidants is necessary for proper physiological function. If free radicals overwhelm the body’s ability to regulate them, a condition known as oxidative stress ensues. Free radicals thus adversely alter lipids, proteins, and DNA and trigger a number of human diseases.

1. These highly reactive structures are present in the membranes of cells of damaging biologically relevant molecules such as DNA, lipids, proteins, carbohydrates, etc.
2. The free radicals attack important macromolecules which lead to cell damage and homeostatic disruption such as proteins, nucleic acids, etc.
3. Generally alkyl halides or aryl halides are used as radical precursors for R or Ar however halogenation of sugars and nucleosides which have many OH groups and other delicate functional groups is rather difficult.
4. The Barton Mccombie reaction is very useful for the radical reactions in sugar nucleosides and peptides.
5. Other thiocarbonyl derivatives formed from alcohols with phenyl thio carbonyl chloride, diimidazole, etc can also be used instead of methyl xanthate.
6. Free radicals are associated with human diseases, including cancer, atherosclerosis, Alzheimer’s disease, Parkinson’s disease, and many others. They also may have a link to aging, which has been defined as a gradual accumulation of free-radical damage
7. The body’s ability to turn air and food into chemical energy depends on a chain reaction of free radicals. Free radicals are also a crucial part of the immune system, floating through the veins and attacking foreign invaders.

Conclusion

 If free radicals overwhelm the body’s ability to regulate them, a condition known as oxidative stress. Free radicals can steal electrons from lipids, proteins, and DNA causing them damage. Antioxidants in the foods we eat can neutralize the unstable molecules, reducing the risk of damage. Because of their high reactivity, they can abstract electrons from other compounds to attain stability.