(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.
Rate
Definition:
(v. t. & i.) To chide with vehemence; to scold; to censure violently.
(n.) Established portion or measure; fixed allowance.
(n.) That which is established as a measure or criterion; degree; standard; rank; proportion; ratio; as, a slow rate of movement; rate of interest is the ratio of the interest to the principal, per annum.
(n.) Valuation; price fixed with relation to a standard; cost; charge; as, high or low rates of transportation.
(n.) A tax or sum assessed by authority on property for public use, according to its income or value; esp., in England, a local tax; as, parish rates; town rates.
(n.) Order; arrangement.
(n.) Ratification; approval.
(n.) The gain or loss of a timepiece in a unit of time; as, daily rate; hourly rate; etc.
(n.) The order or class to which a war vessel belongs, determined according to its size, armament, etc.; as, first rate, second rate, etc.
(n.) The class of a merchant vessel for marine insurance, determined by its relative safety as a risk, as A1, A2, etc.
(v. t.) To set a certain estimate on; to value at a certain price or degree.
(v. t.) To assess for the payment of a rate or tax.
(v. t.) To settle the relative scale, rank, position, amount, value, or quality of; as, to rate a ship; to rate a seaman; to rate a pension.
(v. t.) To ratify.
(v. i.) To be set or considered in a class; to have rank; as, the ship rates as a ship of the line.
(v. i.) To make an estimate.
Example Sentences:
(1) Child benefit has already been withdrawn from higher rate taxpayers.
(2) There was appreciable variation in toothbrush wear among subjects, some reducing their brush to a poor state in 2 weeks whereas with others the brush was rated as "good" after 10 weeks.
(3) Spectral analysis of spontaneous heart rate fluctuations, a powerful noninvasive tool for quantifying autonomic nervous system activity, was assessed in Xenopus Laevis, intact or spinalized, at different temperatures and by use of pharmacological tools.
(4) Propranolol resulted in a significantly lower mean hourly, mean 24 h and minimum heart rate.
(5) The proportion of motile spermatozoa decreased with time at the same rate when samples were prepared in either HEPES or phosphate buffers.
(6) A study of factors influencing genetic counseling attendance rate has been conducted in the Bouches-du-Rhône area, in the south of France.
(7) In this article we report the survival and morbidity rates for all live-born infants weighing 501 to 1000 gram at birth and born to residents of a defined geographic region from 1977 to 1980 (n = 255) compared with 1981 to 1984 (n = 266).
(8) Life expectancy and the infant mortality rate are considered more useful from an operational perspective and for comparisons than is the crude death rate because they are not influenced by age structure.
(9) Heart rate (HR), pulmonary ventilation (V), oxygen consumption (VO2), carbon dioxide production (VCO2), and respiratory quotient (RQ) were measured.
(10) By combined histologic and cytologic examinations, the overall diagnostic rate was raised to 87.7%.
(11) In contrast to previous reports, these tumours were more malignant than osteosarcomas and showed a five-year survival rate of only 4-2 per cent.
(12) A progressively more precise approach to identifying affected individuals involves measuring body weight and height, then energy intake (or expenditure) and finally the basal metabolic rate (BMR).
(13) The second amino acid residue influences not only the rate of reaction but also the extent of formation of the product of the Amadori rearrangement, the ketoamine.
(14) Increased infusion flow rate did not increase the limiting frequency.
(15) The main finding of this study is that diabetic adolescents with a high erythrocyte Na,Li countertransport rate have an arterial pressure significantly higher than patients with normal Na,Li countertransport fluxes.
(16) This clinical improvement was also associated with a decrease of erythrocyte sedimentation rate (p less than 0.001), decrease of C-reactive protein (p less than 0.0001) and with improvement of anaemia (p less than 0.05).
(17) This difference is probably secondary to the different rates of delivery of furosemide into urine.
(18) Under blood preservation conditions the difference of the rates of ATP-production and -consumption is the most important factor for a high ATP-level over long periods.
(19) There is no evidence that health-maintenance organizations reduce admissions in discretionary or "unnecessary" categories; instead, the data suggest lower admission rates across the board.
(20) Male sex, age under 19 or over 45, few social supports, and a history of previous suicide attempts are all factors associated with increased suicide rates.