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
Famous quotes containing the words oxygen and/or species:
“All the oxygen of the world was in them.
All the feet of the babies of the world were in them.
All the crotches of the angels of the world were in them.
All the morning kisses of Philadelphia were in them.”
—Anne Sexton (1928–1974)
“A man can go from being a lover to being a stranger in three moves flat ... but a woman under the guise of friendship will engage in acts of duplicity which come to light very much later. There are different species of self-justification.”
—Anita Brookner (b. 1938)