(n.) That branch of science which treats of the composition of substances, and of the changes which they undergo in consequence of alterations in the constitution of the molecules, which depend upon variations of the number, kind, or mode of arrangement, of the constituent atoms. These atoms are not assumed to be indivisible, but merely the finest grade of subdivision hitherto attained. Chemistry deals with the changes in the composition and constitution of molecules. See Atom, Molecule.
(n.) An application of chemical theory and method to the consideration of some particular subject; as, the chemistry of iron; the chemistry of indigo.
(n.) A treatise on chemistry.
Example Sentences:
(1) It may be due to relative nonreactivity of ascorbic acid free radical that free radical chain reactions, found commonly in radical chemistry, do not occur in the scavenging reaction by ascorbic acid.
(2) We have determined by protein chemistry methods the amino acid sequence of light chain 2 from Acanthamoeba castellanii myosin-II (ALC2).
(3) Reduced mineral absorption is fairly well documented and has sound theoretical support from basic chemistry.
(4) The chemistry involved reaction rate constant measurements of MSF hydrolysis and for reactions with phenolic, amine, oxime, hydroxamic acid, phenyl N-hydroxycarbamate, and hydroxylamine compounds and cupric imidazole and bipyridyl complexes.
(5) 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.
(6) Ion cyclotron resonance spectroscopy yields information on many aspects of ion-molecule chemistry.
(7) --The frequency of common clinical manifestations (eg, headache, fever, and rash) and laboratory findings (eg, leukocyte and platelet counts and serum chemistry abnormalities) of patients with infectious diseases was tabulated.
(8) The reason we have postulated that one-electron oxidation plays an important role in the activation of PAH derives from certain common characteristics of the radical cation chemistry of the most potent carcinogenic PAH.
(9) The fact that sulfinate salts show activity, both ip and po, suggests that the -SO2Na moiety deserves more attention in medicinal chemistry.
(10) Overall adverse reactions were more frequent with the high dose group especially with respect to blood chemistry and gastrointestinal reactions.
(11) There were no significant effects on the haematology, serum chemistry and urinalysis and no compound-related effects on survival.
(12) In a report published online by the journal Atmospheric Chemistry and Physics , experts from Europe and the US estimated that the quantity of the radioactive isotope caesium-137 released at the height of the crisis was equivalent to 42% of that from Chernobyl.
(13) Physiological chemistry stayed a part of physiology until 1939 when the Institute of Physiological Chemistry was finally founded.
(14) Organosilicon chemistry is easily understood because a few generalizations allow us to compare it with the chemistry of carbon, hydrogen and the metals.
(15) Unfortunately, few reflections concern the definition of this criterion, which often is little discussed in the other divisions of the pure and applied chemistry.
(16) Research Institute of Endocrinology and Hormone Chemistry, Khar'kov It was shown that realization of a neoplastic process in the breast is determined, in particular, by the chemical structure of agents employed and their dosage.
(17) There was no change in blood counts or serum chemistry values.
(18) Preoperatively, blood chemistry studies were done in addition to palpation of the abdomen.
(19) Hematologic and clinical chemistry values were similar for all groups.
(20) The TN of some fishes and mammals contains neurons immunoreactive (ir) to gonadotropin-releasing hormone (LHRH), and to several other neuropeptides and neurotransmitter systems, but there is little information on TN chemistry in other vertebrate taxa.
Photochemistry
Definition:
(n.) The branch of chemistry which relates to the effect of light in producing chemical changes, as in photography.
Example Sentences:
(1) Photolysis of the photosystem I particles induces a progressive depletion of phylloquinone, however, photochemistry as assayed at room temperature by the photooxidation of P-700 is unaffected.
(2) Examples have been given for the three possibilities concerning photochemistry of nucleic acids and proteins.
(3) Studies of acrylamide quenching of tryptophan (Trp) fluorescence, photochemistry, and photoionization have been conducted.
(4) These results indicate that plastoquinone functions as the primary electron acceptor of Photosystem II and that beta-carotene does not play a direct role in the primary photochemistry but is required for the C-550 absorbance change.
(5) The photochemistry (Type I and II) of the phototoxic textile dye Disperse Blue (DB-35) and its purified components has been studied using electron spin resonance in conjunction with spin trapping technique and the direct detection of singlet oxygen (1O2) luminescence.
(6) The photochemistry of drugs can be useful (phototherapy) or harmful (phototoxicity).
(7) The photophysics and photochemistry of the 4'-diethylamino derivative of both 2-phenyl-benzothiazole and 2-(2'-hydroxyphenyl)benzothiazole have been studied by nanosecond and microsecond laser flash photolysis and picosecond emission spectroscopy.
(8) The HisM200----Leu RC, which has a heterodimer consisting of a bacteriochlorophyll and a bacteriopheophytin, is capable of the primary photochemistry observed in wild-type Rb.
(9) The photochemistry of benzanthrone (7H-benz[de]-anthracene-7-one) has been studied using electron paramagnetic resonance (EPR) in conjunction with the spin trapping technique and the direct detection of singlet molecular oxygen luminescence.
(10) The results are related to the photochemistry of thymidine and of bacteriophages containing incorporated 5-ethyluracil in place of thymine.
(11) The Hb photochemistry is a complex set of photoreactions leading to successive photoconversions of Hb forms: from oxy- to met- to deoxy- and, finally, to carboxy-form.
(12) The quenching action of dibromothymoquinone on fluorescence and on primary photochemistry was examined in chloroplasts at minus 196 degrees C. Both the initial (F0) and final (FM) levels of fluorescence as well as the fluorescence of variable yield (FV equals FM minus FO) were quenched at minus 196 degrees C to a degree which depended on the concentration of dibromothymoquinone added prior to freezing.
(13) These results were determined through nonlinear least squares regression and residual analyses, with some knowledge of the possible photochemistry of the cofactor by itself.
(14) The photochemistry of trace amounts of isobutene and oxides of nitrogen in an atmosphere of air was studied both in the presence and in the absence of small amounts of carbon monoxide.
(15) The basic law is: "No photobiology--no photochemistry".
(16) The photochemistry of the isolated Photosystem II reaction-centre core from pea and the green alga Scenedesmus was examined by e.s.r.
(17) This information is important not only for the understanding of the basic structure of vitamin A but also the photochemistry of vision.
(18) We have also attempted to do in situ fluorescence spectroscopy on isolated intact eye lenses, which has enabled us to follow the photochemistry and the status of the photoproduct of the oxidation of the trp residues of the crystallins of the lens.
(19) We have studied the photochemistry of the thymine-PABA and thymidine-PABA systems and report here the isolation and characterization of thymine-PABA and thymidine-PABA photoadducts.
(20) This indicates that the high irradiances available from the excimer laser cause the same DNA photochemistry as the lower-irradiance CW sources.