active center


Also found in: Medical.

active center

[′ak·tiv ′sen·tər]
(astronomy)
A localized, transient region of the solar atmosphere in which sunspots, faculae, plages, prominences, solar flares, and so forth are observed.
(biochemistry)
A flexible portion of an enzyme that binds to the substrate and converts it into the reaction product.
In carrier and receptor proteins, the portion of the molecule that interacts with the specific target compounds.
(chemistry)
Any one of the points on the surface of a catalyst at which the chemical reaction is initiated or takes place.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
During the past decade, Bahrain was the Gulf's most active center for mergers and acquisitions in the region with 20 deals consummated, followed by UAE with 19, Kuwait with 12, Qatar with 10, Oman with 7 and Saudi Arabia with one deal.
Since the only difference between the crowed cobalt complexes (CoL1 ~ CoL4) was the size of the crown ether ring (or the number of the ethyleneoxy), it could be deduced that the macrocycle effect of crown ring, which possesses special configuration, would favor oxygen molecule to approach the active center of the Co (II) complexes, and form the Co-O2 bond through its hydrophobic outer ethylene groups and orderly arranged inner aza oxa atoms.
This column describes my experience with using a new classroom space (the ACTIVE Center), which was designed to facilitate group-based active learning and problem solving, to teach an introductory artificial intelligence course.
Cuba has very attractive assets of many kinds." He also thinks Cuba "in due course will be an active center of business in the Caribbean." As for the overall airline industry, Crandall predicted it will be "satisfactorily profitable" for many years thanks not only to low fuel prices but consolidation that has eliminated "extreme competition." Read MoreDelta sees $1.7B benefit from lower fuel costs
Israel's military confirmed the air raid, saying that it had targeted "an active center of terrorism" following a morning rocket attack on southern Israel which caused no casualties or damage.
The full-time 4WD driveline features Mitsubishi Motors' Active Center Differential (ACD) that uses an electronically controlled multi-plate hydraulic clutch to optimally tailor front / rear drive torque vectoring to different driving conditions and deliver the best balance between steering response and traction.
In the second section of the text they describe the application of substrate-inhibitor specificity for calculation of inhibitor selectivity toward different enzymes for identification of reversible and irreversible inhibitors, as well as the use of specificity constants for molecular phylogenetic analysis of the active center of cholinesterases and esterases.
New Rochelle is undergoing a Renaissance that has seen a transformation of its downtown business district into a far more vibrant and active center.
Specially designed Bilstein monotube shocks keep all four wheels planted firmly on the ground, and an electronic active center differential along with a helical-style front limited slip differential make sure that every last horsepower is delivered to those tires.
The basin is the most active center of carbon dioxide (C[O.sub.2]) enhanced oil recovery operations in North America and the world with over 50 such projects in operation.