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Prehydrated Electrons
Prehydrated electrons are free electrons that occur in water under irradiation. Usually they form complexes with water molecules and become hydrated electrons. They can also react with the bases of the nucleotides dGMP and dTMP in aqueous solution. This suggests they may also react with the bases of the DNA double helix, ultimately breaking molecular bonds and causing DNA damage. This mechanism is hypothesized to be a cause of radiation damage to DNA. References {{Reflist Electron Photochemistry Radiation health effects ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron
The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no known components or substructure. The electron's mass is approximately 1/1836 that of the proton. Quantum mechanical properties of the electron include an intrinsic angular momentum ( spin) of a half-integer value, expressed in units of the reduced Planck constant, . Being fermions, no two electrons can occupy the same quantum state, per the Pauli exclusion principle. Like all elementary particles, electrons exhibit properties of both particles and waves: They can collide with other particles and can be diffracted like light. The wave properties of electrons are easier to observe with experiments than those of other particles like neutrons and protons because electrons have a lower mass and hence a longer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrated Electron
A solvated electron is a free electron in (solvated in) a solution, and is the smallest possible anion. Solvated electrons occur widely. Often, discussions of solvated electrons focus on their solutions in ammonia, which are stable for days, but solvated electrons also occur in water and other solvents in fact, in any solvent that mediates outer-sphere electron transfer. The solvated electron is responsible for a great deal of radiation chemistry. Ammonia solutions Liquid ammonia will dissolve all of the alkali metals and other electropositive metals such as Ca, Sr, Ba, Eu, and Yb (also Mg using an electrolytic process), giving characteristic blue solutions. For alkali metals in liquid ammonia, the solution is blue when dilute and copper-colored when more concentrated (> 3 molar). These solutions conduct electricity. The blue colour of the solution is due to ammoniated electrons, which absorb energy in the visible region of light. The diffusivity of the solvated elec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleotide
Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules within all life-forms on Earth. Nucleotides are obtained in the diet and are also synthesized from common nutrients by the liver. Nucleotides are composed of three subunit molecules: a nucleobase, a five-carbon sugar ( ribose or deoxyribose), and a phosphate group consisting of one to three phosphates. The four nucleobases in DNA are guanine, adenine, cytosine and thymine; in RNA, uracil is used in place of thymine. Nucleotides also play a central role in metabolism at a fundamental, cellular level. They provide chemical energy—in the form of the nucleoside triphosphates, adenosine triphosphate (ATP), guanosine triphosphate (GTP), cytidine triphosphate (CTP) and uridine triphosphate (UTP)—throughout the cell for the many c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deoxyguanosine Monophosphate
Deoxyguanosine monophosphate (dGMP), also known as deoxyguanylic acid or deoxyguanylate in its conjugate acid and conjugate base forms, respectively, is a derivative of the common nucleic acid guanosine triphosphate (GTP), in which the –OH ( hydroxyl) group on the 2' carbon on the nucleotide's pentose has been reduced to just a hydrogen atom (hence the "deoxy-" part of the name). It is used as a monomer in DNA. See also * Cofactor * Guanosine *Nucleic acid Nucleic acids are biopolymers, macromolecules, essential to all known forms of life. They are composed of nucleotides, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main cl ... References Nucleotides {{Biochemistry-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deoxyguanosine Triphosphate
Deoxyguanosine triphosphate (dGTP) is a nucleoside triphosphate, and a nucleotide precursor used in cells for DNA synthesis. The substance is used in the polymerase chain reaction technique, in sequencing, and in cloning. It is also the competitor of inhibition onset by acyclovir in the treatment of HSV virus A virus is a wikt:submicroscopic, submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and .... References Nucleotides Phosphate esters {{Organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleic Acid Double Helix
Nucleus ( : nuclei) is a Latin word for the seed inside a fruit. It most often refers to: *Atomic nucleus, the very dense central region of an atom * Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA Nucleus may also refer to: Science, technology, and mathematics Astronomy *Active galactic nucleus in astronomy *Comet nucleus, the solid, central part of a comet Biology * Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA *Nucleus (neuroanatomy), a cluster of cell bodies of neurons in the central nervous system *Nucleus that forms in the eye in nuclear sclerosis (early cataracts) *''Nucleus'', a scientific journal concerned with the cell nucleus; published by Taylor & Francis *Nucleus, a small colony of honeybees, induced to raise a new queen by the beekeeper Computer systems * Nucleus (operating system), sometimes a synonym for kernel * Nucleus CMS, a weblog system * Nucleus RTOS, a real-time ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron
The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no known components or substructure. The electron's mass is approximately 1/1836 that of the proton. Quantum mechanical properties of the electron include an intrinsic angular momentum ( spin) of a half-integer value, expressed in units of the reduced Planck constant, . Being fermions, no two electrons can occupy the same quantum state, per the Pauli exclusion principle. Like all elementary particles, electrons exhibit properties of both particles and waves: They can collide with other particles and can be diffracted like light. The wave properties of electrons are easier to observe with experiments than those of other particles like neutrons and protons because electrons have a lower mass and hence a longer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photochemistry
Photochemistry is the branch of chemistry concerned with the chemical effects of light. Generally, this term is used to describe a chemical reaction caused by absorption of ultraviolet (wavelength from 100 to 400 nm), visible light (400–750 nm) or infrared radiation (750–2500 nm). In nature, photochemistry is of immense importance as it is the basis of photosynthesis, vision, and the formation of vitamin D with sunlight. Photochemical reactions proceed differently than temperature-driven reactions. Photochemical paths access high energy intermediates that cannot be generated thermally, thereby overcoming large activation barriers in a short period of time, and allowing reactions otherwise inaccessible by thermal processes. Photochemistry can also be destructive, as illustrated by the photodegradation of plastics. Concept Grotthuss–Draper law and Stark-Einstein law Photoexcitation is the first step in a photochemical process where the reactant is elevat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
