(n.) A process by which reaction occurs in the presence of certain agents which were formerly believed to exert an influence by mere contact. It is now believed that such reactions are attended with the formation of an intermediate compound or compounds, so that by alternate composition and decomposition the agent is apparenty left unchanged; as, the catalysis of making ether from alcohol by means of sulphuric acid; or catalysis in the action of soluble ferments (as diastase, or ptyalin) on starch.
(n.) The catalytic force.
Example Sentences:
(1) Nucleotide, which is essential for catalysis, greatly enhances the binding of IpOHA by the reductoisomerase, with NADPH (normally present during the enzyme's rearrangement step, i.e., conversion of a beta-keto acid into an alpha-keto acid, in either the forward or reverse physiological reactions) being more effective than NADP.
(2) The physiologically important metal ion for catalysis is Mg2+; however, Mn2+ supports in vitro activity, though at a reduced level.
(3) High intensity ultrasound also enhances the heterogeneous catalysis of alkene hydrogenation by Ni powders.
(4) We support the view that catalysis by metalloenzymes may be a reflection of the chemistry of the metal ion itself as a Lewis acid, and that perhaps too much emphasis has been placed on supposed special characteristics (such as strains, "entasis") of the enzyme-metal ion association.
(5) With copper-ion catalysis, ligands inhibit competitively.
(6) Clearly the cysteines play no essential role in catalysis or cyclosporin A binding.
(7) Some mechanisms that can provide catalysis of phosphoryl transfer through a metaphosphate-like transition state are reviewed briefly.
(8) To investigate the ability of a protein to accommodate potentially destabilizing amino acid substitutions, and also to investigate the steric requirements for catalysis, proline was substituted at different sites within the long alpha-helix that connects the amino-terminal and carboxyl-terminal domains of T4 lysozyme.
(9) The C-terminal domain (327 amino acids) is responsible for catalysis and binds the two zinc ions, which are 2.88 A apart.
(10) Determination of the rate of CO2 production permitted the calculation of capillary blood volume, mean capillary transit time, and the degree of catalysis of CO2 reactions by carbonic anhydrase present in the lung.
(11) The species invariance of this lysine residue, number 175, and the substantial conservation of adjacent sequence support the probability for a functional role in catalysis of the lysyl epsilon-amino group.
(12) Catalysis is processive at optimum salt concentration and distributive at a higher one; camptothecin decreases the initial rate of reaction in both salt conditions, but more so at the higher one.
(13) No evidence for the participation of the fully reduced flavoprotein in catalysis could be obtained.
(14) Additional studies reported here showed that acylation of PLA2 was not necessary for catalysis or binding to the interface and that the binding of the substrate to the active site of PLA2 was not necessary for the binding of the enzyme to the interface.
(15) The UTP concentration dependence for photolabeling was the same as that for promoting catalysis.
(16) The extent catalysis of phosphodiester bond formation varied with the particular clay mineral used.
(17) Comparison of the specific activities for aniline hydroxylation and p-nitrophenol hydroxylation of individual microsomal samples from control, ethanol-pretreated and phenobarbital-pretreated animals showed a high degree of correlation (r2 = 0.98) consistent with the involvement of the same site for catalysis of these two compounds.
(18) Limited data indicates that, while enhanced thermal stability invariably results, the optimum temperature for catalysis may not change.
(19) These results suggest that two convalent intermediates, phosphoryl and malonyl enzyme, are sequentially formed in the synthesis of malonyl-coenzyme A by malonyl-coenzyme A synthetase catalysis.
(20) During catalysis in the scooting mode the enzyme does not leave the surface of the vesicle to which it is bound.
Catalyst
Definition:
Example Sentences:
(1) The radioprotective action in E. coli ATCC 9637 of ascorbate added to media containing the weak sensitizer, tetracycline (effect described by Pittillo and Lucas (1967)), was found to be dependent on the presence of metal catalysts of the autoxidation of ascorbate.
(2) "If I hadn't scored that goal, I might still have ended up playing in Italy [Platt went on to play for Bari, Juventus and Sampdoria] but, realistically, I'm sure it was the catalyst.
(3) Enzymes are good catalysts in terms of high catalytic and specific activity with ability to function under mild conditions.
(4) The main aim of this brief contribution is to suggest that our understanding of the general principles of osmochemistry may provide useful insights into the type of mechanism by which solute-translocating catalysts work.
(5) Shelby Quast, of Equality Now, said the gathering could be a “tipping point” and act as a catalyst for change, so that girls in the US could finally be protected: “It’s the first time that members of the government are coming around the table to meet with civil society, survivors and members of the diaspora – this is the first step towards putting together a comprehensive action plan to tackling FGM.” Campaigners are calling for the government to look at practical ways that FGM could be wiped out in the United States – such as engaging with paediatricians and other doctors, immigration officers and visa offices.
(6) With different oxidation catalysts most antioxidants and amino acids tested enhanced polymerization.
(7) The high sites' density with basic character, evidenced by use of various probe molecules, is very similar for the two asbestos types (chrysotile and crocidolite) and on the same order as the density encountered in some catalysts.
(8) Fillings were made of Concise composite resin, without applying an intermediary resin (1), after applying the resin layer (2), after diluting the mix with one (3) or two (4) drops of catalyst resin but without an intermediary resin, and after diluting the mix and applying the resin layer (5).
(9) Monoclonal antibodies elicited to haptens that are analogs of the transition state for hydrolysis of carboxylic esters behaved as enzymic catalysts with the appropriate substrates.
(10) Rapid addition of purines and pyrimidines to alpha, beta-unsaturated carbonyl compounds (such as acrolin) is a general phenomenon which does not require an amine catalyst.
(11) Time acts as a catalyst for members to learn to respect and appreciate each other.
(12) The resulting solution is directed into tubes containing a catalyst that is activated by UV light and causes the dissolved CO2 to react with water (H2O) to form methanol (CH3OH).
(13) Manganese therefore acts as a catalyst for the non-enzymatic reaction, but magnesium does not.
(14) When the reaction was done in dimethyl sulfoxide, with 1-methylimidazole as the catalyst, a third compound was observed, and identified as 1,2,4-tri-O-acetyl-3-C-(acetoxymethyl)-3-O-(methylthiomethyl)-D-glycero- tetrito l [3-O-(methylthiomethyl)apiitol tetraacetate] by gas-liquid chromatography and mass spectrometry.
(15) Russell also described the Commonwealth Games as a catalyst but was realistic enough not to claim they immediately changed an area with long, deep-rooted problems, or miraculously roused a poor, generally unhealthy local population into vigorously playing sport.
(16) The device limits the amount of oxygen entering with the sample to a maximum of 2%, which is rapidly removed by reacting with hydrogen in the presence of a palladium catalyst.
(17) The yields of Thf-FU and more especially of Thf2-FU were greatly dependent on the relative amount of SnCl4, and 0.01-0.1 equiv of the catalyst with respect to Me3Si-FU gave the best results.
(18) Some officers close to the case believe George and Allen may have always harboured paedophilic thoughts but Blanchard provided a "catalyst" which encouraged them to act out their fantasies.
(19) Dusan Tadic was introduced at the break and looked a catalyst for a comeback.
(20) These findings may indicate that trace amounts of acidic catalysts remaining after production of IPM are responsible for the toxic effect.