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The hydroxyl radical can damage virtually all types of macromolecules: carbohydrates, nucleic acids , lipids (lipid peroxidation) and amino acids (e.g. conversion of Phe to m-Tyrosine and o-Tyrosine). The hydroxyl radical has a very short in vivo half-life of approximately 10 −9 seconds and a high reactivity. [5]
In chemistry, a radical, also known as a free radical, is an atom, molecule, or ion that has at least one unpaired valence electron. [1] [2] With some exceptions, these unpaired electrons make radicals highly chemically reactive. Many radicals spontaneously dimerize. Most organic radicals have short lifetimes.
As ionizing radiation moves through matter its energy is deposited through interactions with the electrons of the absorber. [1] The result of an interaction between the radiation and the absorbing species is removal of an electron from an atom or molecular bond to form radicals and excited species. The radical species then proceed to react with ...
On the other hand, physical chemistry deals with the physical properties and behavior of matter in chemical reactions, covering a broader range of topics such as thermodynamics, kinetics, and spectroscopy, and often links the macroscopic and microscopic chemical behavior. The distinction between the two fields still needs to be clarified as ...
An atom with a dangling bond is also referred to as an immobilized free radical or an immobilized radical, a reference to its structural and chemical similarity to a free radical. When speaking of a dangling bond, one is generally referring to the state described above, containing one electron and thus leading to a neutrally charged atom.
Example radical: Structure of Hydrocarboxyl radical, lone electron indicated as single black dot. A radical is a molecule with an odd number of electrons, and is induced in a variety of ways, including ultraviolet radiation. A sun burn is largely due to radical formation from this radiation. The radical-pair, however, is not simply two radicals.
Chemistry is the scientific study of the properties and behavior of matter. [1] It is a physical science within the natural sciences that studies the chemical elements that make up matter and compounds made of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during reactions with other substances.
Particle physics or high-energy physics is the study of fundamental particles and forces that constitute matter and radiation. The field also studies combinations of elementary particles up to the scale of protons and neutrons , while the study of combination of protons and neutrons is called nuclear physics .