Related topics: cells · mitochondria · antioxidants

Key to carbon-free cars? Look to the stars

For nearly half a century, astrophysicists and organic chemists have been on the hunt for the origins of C6H6, the benzene ring—an elegant, hexagonal molecule comprised of 6 carbon and 6 hydrogen atoms.

Innovative light therapy reaches deep tumors

Light long has been used to treat cancer. But phototherapy is only effective where light easily can reach, limiting its use to cancers of the skin and in areas accessible with an endoscope, such as the gastrointestinal tract.

Nano-antioxidants prove their potential

Injectable nanoparticles that could protect an injured person from further damage due to oxidative stress have proven to be astoundingly effective in tests to study their mechanism.

Safeguarding genome integrity through extraordinary DNA repair

( -- DNA is under constant attack, from internal factors like free radicals and external ones like ionizing radiation. About 10 double-strand breaks – the kind that snap both backbones of the double helix ...

A radical new approach in synthetic chemistry

Scientists at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory helped measure how unpaired electrons in atoms at one end of a molecule can drive chemical reactivity on the molecule's opposite side. As ...

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Radical (chemistry)

In 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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