Activator (other)
Activator may refer to: * Activator (genetics), a DNA-binding protein that regulates one or more genes by increasing the rate of transcription * Activator (phosphor), a type of dopant used in phosphors and scintillators * Enzyme activator, a type of effector that increases the rate of enzyme mediated reactions * Sega Activator, a motion-sensing controller for the Sega Mega Drive/Genesis * Activator technique, a method of spinal adjustment * Activator appliance, an orthodontic functional appliance See also * Activate (other) * Activation In chemistry and biology, activation is the process whereby something is prepared or excited for a subsequent reaction. Chemistry In chemistry, "activation" refers to the reversible transition of a molecule into a nearly identical chemical or ...

Activator (genetics)
A transcriptional activator is a protein (transcription factor) that increases transcription of a gene or set of genes. Activators are considered to have ''positive'' control over gene expression, as they function to promote gene transcription and, in some cases, are required for the transcription of genes to occur. Most activators are DNA-binding proteins that bind to enhancers or promoter-proximal elements. The DNA site bound by the activator is referred to as an "activator-binding site". The part of the activator that makes protein–protein interactions with the general transcription machinery is referred to as an "activating region" or "activation domain". Most activators function by binding sequence-specifically to a regulatory DNA site located near a promoter and making protein–protein interactions with the general transcription machinery (RNA polymerase and general transcription factors), thereby facilitating the binding of the general transcription machinery to the ...
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Activator (phosphor)
In phosphors and scintillators, the activator is the element added as dopant to the crystal of the material to create desired type of nonhomogeneities. In luminescence, only a small fraction of atoms, called emission centers or luminescence centers, emit light. In inorganic phosphors, these inhomogeneities in the crystal structure are created usually by addition of a trace amount of dopants, impurities called activators. (In rare cases dislocations or other crystal defects can play the role of the impurity.) The wavelength emitted by the emission center is dependent on the atom itself, its electronic configuration, and on the surrounding crystal structure. The activators prolong the emission time (afterglow). In turn, other materials (such as nickel) can be used to quench the afterglow and shorten the decay part of the phosphor emission characteristics. The electronic configuration of the activator depends on its oxidation state and is crucial for the light emission. Oxidation of ...
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Enzyme Activator
Enzyme activators are molecules that bind to enzymes and increase their activity. They are the opposite of enzyme inhibitors. These molecules are often involved in the allosteric regulation of enzymes in the control of metabolism Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the co .... In some cases, when a substrate binds to one catalytic subunit of an enzyme, this can trigger an increase in the substrate affinity as well as catalytic activity in the enzyme's other subunits, and thus the substrate acts as an activator. Examples Phosphofructokinase 1 An example of an enzyme activator working in this way is fructose 2,6-bisphosphate, which activates phosphofructokinase 1 and increases the rate of glycolysis in response to the hormone glucagon. Hexokinase-I Hexokinase-I ( ...
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Sega Activator
The Sega Genesis, known as the outside North America, is a 16-bit fourth generation home video game console developed and sold by Sega. It was Sega's third console and the successor to the Master System. Sega released it in 1988 in Japan as the Mega Drive, and in 1989 in North America as the Genesis. In 1990, it was distributed as the Mega Drive by Virgin Mastertronic in Europe, Ozisoft in Australasia, and Tectoy in Brazil. In South Korea, it was distributed by Samsung Electronics as the Super Gam*Boy and later the Super Aladdin Boy. Designed by an R&D team supervised by Hideki Sato and Masami Ishikawa, the Genesis was adapted from Sega's System 16 arcade board, centered on a Motorola 68000 processor as the CPU, a Zilog Z80 as a sound controller, and a video system supporting hardware sprites, tiles, and scrolling. It plays a library of more than 900 games on ROM-based cartridges. Several add-ons were released, including a Power Base Converter to play Master System gam ...
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