| ligand-gated channel | A class of ion channel's whose ionic permeability is regulated by cell membrane receptors that respond to specific extracellular chemical signals. (05 Mar 2000) |
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| Alfven ion cyclotron instability | <radiobiology> An electromagnetic microinstability near the ion cyclotron frequency, driven by the ion loss cone in a mirror device. Acronym: AIC (13 Nov 1997) |
| aquo-ion | A hydrated ion; an ion containing one or more water molecules; e.g., Cu(H2O)42+. (05 Mar 2000) |
| central metal ion | <chemistry> The metal ion to which the ligands are attached at the centre of a coordination complex. (09 Oct 1997) |
| gram-ion | <chemistry> The weight in grams of an ion that is equal to the sum of the atomic weights of the atoms making up the ion. (05 Mar 2000) |
| chromatography, ion exchange | Separation technique in which the stationary phase consists of ion exchange resins. The resins contain loosely held small ions that easily exchange places with other small ions of like charge present in solutions washed over the resins. (12 Dec 1998) |
| mobile ion carrier | <chemistry> A molecule that allows ions to cross lipid bilayers. There are two classes: carriers and channels. Carriers, like valinomycin, form cage like structures around specific ions, diffusing freely through the hydrophobic regions of the bilayer. Channels, like gramicidin, form continuous aqueous pores through the bilayer, allowing ions to diffuse through. See: ion channels. (18 Nov 1997) |
| common ion effect | <chemistry> The influence on an equilibrium by the presence of a substance which contains ions that participate in the equilibrium. (09 Oct 1997) |
| complex ion | The colour, texture, and general appearance of the skin of the face. Origin: L. Complexio, a combination, (later) physical condition (05 Mar 2000) Previous: complex carbohydrate, complex closure, complex febrile convulsion, complexinNext: complex ion, complexity, complex learning processescomplex ion <chemistry> An ion formed by the combination of a central metal ion and ligands. (05 Jan 1998) |
| Heavy Ion Beams | <radiobiology> Particle beams using heavy (as opposed to light) ions. These can be used for inertial confinement fusion research. (10 Jan 1998) |
| P with a subscript for the ion | <abbreviation> Permeability constant. (05 Mar 2000) |
| hydride ion | The H- i., transferred to acceptor molecules in some biological oxidations. (05 Mar 2000) |
| hydrogen ion | A hydrogen atom minus its electron and therefore carrying a unit positive charge (i.e., a proton); in water, it combines with a water molecule to form hydronium ion, H3O+. (05 Mar 2000) |
| hydronium ion | <chemistry> A positively charged ion that is water with an additional hydrogen atom (H3O). (09 Oct 1997) |
| spectrometry, mass, secondary ion | A mass-spectrometric technique that is used for microscopic chemical analysis. A beam of primary ions with an energy of 5-20 kiloelectronvolts (kev) bombards a small spot on the surface of the sample under ultra-high vacuum conditions. Positive and negative secondary ions sputtered from the surface are analyzed in a mass spectrometer in regards to their mass-to-charge ratio. (12 Dec 1998) |