When an electron inside a cell becomes unpaired, it creates a free radical. Free radicals are highly reactive molecules or atoms that have an unpaired electron. These unpaired electrons cause the free radical to seek out other electrons to stabilize itself, which can lead to chemical reactions that damagecells, proteins, and DNA.

In biological systems, free radicals are often associated with oxidative stress, a condition where the balance between free radicals and antioxidants is disrupted, leading to cellular damage. This damage can contribute to aging and various diseases, including cancer, neurodegenerative disorders, and cardiovascular diseases.

Cells have mechanisms to mitigate the damage caused by free radicals, such as producing antioxidants that neutralize them. However, if the production of free radicals exceeds the cell's ability to manage them, it can lead to significant cellular dysfunction or death.