Related topics: cells · mitochondria · antioxidants

Scientists discover how mitochondria import antioxidants

Many of the processes that keep us alive also put us at risk. The energy-producing chemical reactions in our cells, for example, also produce free radicals—unstable molecules that steal electrons from other molecules. When ...

Better understanding air pollution mechanisms

Earth's atmosphere has a budget, and when expenses outpace savings, secondary aerosols form in areas of excessive pollution. Greenhouse gases enter the atmosphere, and free radicals bond to the molecules, rendering them inert. ...

New method makes generic polymers luminescent

Researchers from Hokkaido University have successfully developed a new method to give luminescent properties to generic polymers, such as polystyrene and polyethylene. The technique, which was published in the journal Angewandte ...

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.

page 1 from 14

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.

This text uses material from Wikipedia, licensed under CC BY-SA