Radical (chemistry)
hideIn chemistry, radicals (often referred to as free radicals) are atoms, molecules, or ions with unpaired electrons on an otherwise open shell configuration. These unpaired electrons are usually highly reactive, so radicals are likely to take part in chemical reactions. Radicals play an important role in combustion, atmospheric chemistry, polymerization, plasma chemistry, biochemistry, and many other chemical processes, including human physiology. For example, superoxide and nitric oxide regulate many biological processes, such as controlling vascular tone. "Radical" and "free radical" are frequently used interchangeably, although a radical may be trapped within a solvent cage or be otherwise bound. The first organic free radical identified was triphenylmethyl radical, by Moses Gomberg in 1900 at the University of Michigan.
Historically, the term radical has also been used for bound parts of the molecule, especially when they remain unchanged in reactions. These are now called functional groups. For example, methyl alcohol was described as consisting of a methyl "radical" and a hydroxyl "radical". Neither are radicals in the modern chemical sense, as they are permanently bound to each other, and have no unpaired, reactive electrons. They can, however, be observed as radicals in mass spectrometry after breaking down the substance with a hail of energetic electrons.
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News tagged with free radicals
Killer carbs -- Monash scientist finds the key to overeating as we age
Aug 21, 2008 |
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A Monash University scientist has discovered key appetite control cells in the human brain degenerate over time, causing increased hunger and potentially weight-gain as we grow older.
Newly detected air pollutant mimics damaging effects of cigarette smoke
Aug 17, 2008 |
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A previously unrecognized group of air pollutants could have effects remarkably similar to harmful substances found in tobacco smoke, Louisiana scientists are reporting in a study scheduled for presentation ...
Probing Question: How do antioxidants work?
Aug 01, 2008 |
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Blueberries, pomegranates, green tea and dark chocolate -- these are just some of the antioxidant-rich "superfoods" found in almost any supermarket today. As well as improving our general health, there is growing evidence ...
Cutting calories could limit muscle wasting in later years
Sep 16, 2008 |
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Chemical concoctions can smooth over wrinkles and hide those pesky grays, but what about the signs of aging that aren't so easy to fix, such as losing muscle mass? Cutting calories early could help, say University of Florida ...
Mouse studies suggest daily dose of ginkgo may prevent brain cell damage after a stroke
Oct 09, 2008 |
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Working with genetically engineered mice, researchers at Johns Hopkins have shown that daily doses of a standardized extract from the leaves of the ginkgo tree can prevent or reduce brain damage after an induced stroke.
Forget the antioxidants? Researchers cast doubt on role of free radicals in aging
Biology /
Feb 17, 2009 |
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For more than 40 years, the prevailing explanation of why we get old has been tied to what is called oxidative stress. This theory postulates that when molecules like free radicals, oxygen ions and peroxides build up in cells, ...
Brain plays key role in appetite by regulating free radicals
Jul 30, 2008 |
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Researchers at Yale School of Medicine have found the brain's appetite center uses fat for fuel by involving oxygen free radicals—molecules associated with aging and neurodegeneration. The findings, reported in the journal ...
Chocolate cuts death rate in heart attack survivors: study
Aug 13, 2009 |
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Heart attack survivors who eat chocolate two or more times per week cut their risk of dying from heart disease about threefold compared to those who never touch the stuff, scientists have reported.
Living longer and happier
Aug 19, 2009 |
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A new study from the University of Missouri may shed light on how to increase the level and quality of activity in the elderly. In the study, published in this week's edition of Public Library of Science - ONE, MU resear ...
How cells die determines whether immune system mounts response
Jul 17, 2008 |
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Every moment we live, cells in our bodies are dying. One type of cell death activates an immune response while another type doesn't. Now researchers at Washington University School of Medicine in St. Louis and St. Jude's ...
Source of major health benefits in olive oil revealed
Apr 02, 2009 |
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Scientists have pinned down the constituent of olive oil that gives greatest protection from heart attack and stroke. In a study of the major antioxidants in olive oil, Portuguese researchers showed that one, DHPEA-EDA, protects ...
Road rage: Fuel vapor heightens aggression
Nov 24, 2009 |
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Outrageous prices may not be the only thing causing anger at the petrol pumps. A new study, published in the open access journal BMC Physiology, has shown that rats exposed to fumes from leaded and unleaded gasoline become ...
Broccoli may help protect against respiratory conditions like asthma
Mar 02, 2009 |
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Here's another reason to eat your broccoli: UCLA researchers report that a naturally occurring compound found in broccoli and other cruciferous vegetables may help protect against respiratory inflammation ...
Toward a systems biology map of iron metabolism
Apr 28, 2009 |
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Scientists at the Wake Forest University School of Medicine, the University of Manchester in the United Kingdom, and the Virginia Bioinformatics Institute at Virginia Tech have taken the first steps toward constructing a ...
Tiny particles can deliver antioxidant enzyme to injured heart cells
Nov 16, 2009 |
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Researchers at Emory University and the Georgia Institute of Technology have developed microscopic polymer beads that can deliver an antioxidant enzyme made naturally by the body into the heart.
