Related topics: cells · mitochondria · antioxidants

Fluorescent molecule betrays the breakdown of polymer materials

Nylon, rubber, silicone, Teflon, PVC—these are all examples of man-made polymers—long chains of repeated molecular units that we call monomers. While polymers also exist in nature (think wool, silk, or even hair), the ...

Nanomaterials based strategies for treatment of hypoxic tumor

Hypoxia is a typical characteristic of most tumors, owing to the fast consumption of oxygen by tumor tissue over the supply through malformed and abnormal tumor vasculature. Hypoxia in tumor tissue promotes the probability ...

Scientists create sensors with traps for free radicals

Scientists of Tomsk Polytechnic University and partners from the Czech Republic and France have designed extremely sensitive sensors for free oxygen-containing radicals that are able to disrupt cell function. According to ...

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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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