vapaakradikaali

Vapaakradikaali, meaning "free radical" in Finnish, refers to an atom, molecule, or ion that possesses at least one unpaired valence electron. This unpaired electron makes the species highly reactive and unstable. Free radicals are typically formed during chemical reactions, such as oxidation-reduction processes or in the presence of radiation.

In biological systems, free radicals are a natural byproduct of metabolic processes. While some free radicals play crucial roles in cellular signaling and immune responses, an excessive accumulation can lead to oxidative stress. Oxidative stress occurs when the production of free radicals overwhelms the body's antioxidant defenses, potentially causing damage to cellular components like DNA, proteins, and lipids. This damage has been implicated in the aging process and the development of various diseases, including cardiovascular disease, cancer, and neurodegenerative disorders.

The formation of free radicals can also be influenced by external factors such as exposure to environmental pollutants, cigarette smoke, and ultraviolet radiation. The body possesses a defense system of antioxidants, which are molecules that can neutralize free radicals by donating an electron to the unpaired electron, thereby stabilizing the radical. Examples of antioxidants include vitamins C and E, as well as enzymes produced by the body. Maintaining a balance between free radical production and antioxidant defenses is essential for cellular health.