Reactive oxygen species (ROS) are chemically reactive molecules containing oxygen. Examples include oxygen ions and peroxides. ROS form as a natural byproduct of the normal metabolism of oxygen and have important roles in cell signaling and homeostasis. However, during times of environmental stress (e.g., UV or heat exposure), ROS levels can increase dramatically. This may result in significant damage to cell structures. Cumulatively, this is known as oxidative stress. ROS are also generated by exogenous sources such as ionizing radiation.
Read more about Reactive Oxygen Species: Signaling and Damaging Effects, Internal Production, Cause of Aging, Superoxide Dismutase, ROS-directed Cancer Chemotherapeutics
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—Anne Sexton (1928–1974)
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