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.
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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)
“The question that will decide our destiny is not whether we shall expand into space. It is: shall we be one species or a million? A million species will not exhaust the ecological niches that are awaiting the arrival of intelligence.”
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