Free radicals

Free radicals are atoms, molecules, or ions with unpaired electrons on an otherwise open shell configuration. These unpaired electrons are usually highly reactive, which can lead to a variety of harmful effects in biological systems.

Chemical Characteristics

Free radicals are characterized by their high reactivity. This is due to the presence of unpaired electrons, which are not bound to any particular atom and are therefore free to interact with other atoms or molecules. This can lead to chemical reactions that can be harmful to biological systems.

Biological Effects

In biological systems, free radicals can cause damage to parts of cells such as proteins, DNA, and cell membranes by stealing their electrons through a process called oxidation. This can lead to cell damage and death, and is thought to play a role in aging and various health conditions such as cancer, heart disease, and neurodegenerative diseases.

Free Radical Theory of Aging

The Free Radical Theory of Aging posits that the accumulation of free radicals over time causes the damage that leads to aging. This theory is supported by evidence showing that organisms with longer lifespans tend to produce fewer free radicals.

Antioxidants

Antioxidants are molecules that can donate an electron to a free radical without becoming destabilized themselves, thereby neutralizing the free radical and preventing it from causing damage. The body produces some antioxidants itself, but they can also be obtained through diet.

See Also

• Oxidative stress
• Reactive oxygen species
• Redox reactions
• Antioxidant therapy