free radical


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free radical

n.
An atom or group of atoms that has at least one unpaired electron and is therefore unstable and highly reactive. In animal tissues, free radicals can damage cells and are believed to accelerate the progression of cancer, cardiovascular disease, and age-related diseases.

free radical

n
(Chemistry) an atom or group of atoms containing at least one unpaired electron and existing for a brief period of time before reacting to produce a stable molecule. Sometimes shortened to: radical Compare group10

free′ rad′ical


n.
a molecular fragment that bears one or more unpaired electrons and is therefore highly reactive.
[1895–1900]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.free radical - an atom or group of atoms with at least one unpaired electron; in the body it is usually an oxygen molecule that has lost an electron and will stabilize itself by stealing an electron from a nearby molecule; "in the body free radicals are high-energy particles that ricochet wildly and damage cells"
atom - (physics and chemistry) the smallest component of an element having the chemical properties of the element
References in periodicals archive ?
This study appears in the journal Free Radical Biology and Medicine.
If an atom gives up an electron and can't find one to take its place, it becomes a free radical, eager to scavenge electrons to fill the empty slot.
'With aging', adds Begdache, 'there is an increase in free radical formation (oxidants), so our need for antioxidants increases.
Free radical scavenging activity was assessed by mixing 300 ul of test sample with 3.0 ml of ABTS working standard in a micro cuvette.
"Our research studied both the Arabica coffee bean itself and what happens to its stable free radical and antioxidant properties during the brewing process," Dr Troup said.
The researchers exposed baby mice to a type of free radical found in air pollution, which triggered Ahr.
He developed the "Free Radical Theory of Aging" in 1954.
Once a free radical joins with an antioxidant, it is stable.
The interactions of the heated bismuth subgallate with free radicals were examined by the use of DPPH (2,2-diphenyl-1-picrylhydrazyl) as the model free radical reference.
Now, about those skin creams with potentially harmful additives: topically applied products that contain high levels of allergens can increase free radical damage in your skin.
Though phenomenal literature and huge theories of ageing are put forward, the most recent and highly accepted theory is "Free Radical Theory of Ageing" conceived by Harman.[1] In the free radical theory of aging, there is some imbalance between production and scavenging mechanisms of free radicals.[2] The free radical theory of aging proposes that reactive oxygen species (ROS) cause oxidative damage over the lifetime of the subject which is critical in determining the life span.[3] It is the cumulative and potentially increasing amount of accumulated damage that accounts for the dysfunctions and pathologies seen in normal aging.