What's the difference between isomerism and substance?

Isomerism


Definition:

  • (n.) The state, quality, or relation, of two or more isomeric substances.

Example Sentences:

  • (1) Structure assignment of the isomeric immonium ions 5 and 6, generated via FAB from N-isobutyl glycine and N-methyl valine, can be achieved by their collision induced dissociation characteristics.
  • (2) This is interpreted to mean that the release of fructose from the central complex is faster than the isomerization of the E-NADH complex.
  • (3) The optical and oxygen binding properties of the reconstituted myoglobins containing two isomeric monoformyl-monovinylhemins were found to be different.
  • (4) Line broadening detected in several of the high-field nuclear magnetic resonance spectra was attributed to cis-trans isomerization.
  • (5) Two new isomeric delta-lactones 2 and 3 have been isolated from the marine fungus Helicascus kanaloanus (ATCC 18591).
  • (6) Two isomeric hydrolysis products of this compound with only three 3(R)-hydroxymyristic acid moieties attached to the disaccharide-1-phosphate were also identified.
  • (7) Studies on the metabolism of nicotine by rabbit liver microsomal fractions in the presence of 0.01 M sodium cyanide have led to the characterization of two isomeric cyanonicotine compounds.
  • (8) Kinetic methods are outlined for the distinction between two pathways of substrate binding, which include an isomerization either of the free enzyme or of the enzyme-substrate complex.
  • (9) In the case of H101S, a mutant protein with measurable isomerizing activity, substrate binding with novel fluorescent properties was observed, possibly the bound pyranose form of xylose under steady-state conditions.
  • (10) There were consistent isomeric preferences for the R(-) configuration of both DA analogs in stimulating adenylate cyclase (D-1 sites) and in competing for high affinity binding of 3H-spiroperidol (D-2 sites) and of 3H-ADTN (DA agonist binding sites) in striatal tissue, with lesser isomeric differences in the limbic tissue.
  • (11) Oligosaccharides 3 and 4 and oligosaccharides 5 and 6 were isolated as unresolved isomeric mixtures in fractions B3a and B4a, respectively.
  • (12) Subsequent fractionation of the original compound into its two isomeric forms resulted in the identification of the isomer primarily responsible for this convulsive activity.
  • (13) However, the 1500 K simulation produced higher energy structures, even after minimization; in addition, this highest temperature run had many cis-trans peptide isomerizations.
  • (14) From model compound data, it is shown that the expected rate for isomerism is in satisfactory agreement with the rates actually observed for protein folding.
  • (15) Re-analysis of PCP and PCP-Na samples with high PCDD contents on a high-resolution glass capillary column showed the presence of 3 hexa- and the 2 heptachlorodibenzo-p-dioxins with nearly constant isomeric ratios.
  • (16) Such a genomic structure does not appear to have been reported amongst the herpesviruses--all the genomes that do not isomerize either have repeat structures only at the termini, or if present internally, have only direct repeats.
  • (17) The isomeric N,N-dimethyl-4,5-diphenyl-1H-pyrazole-1-propanamine was completely inactive in the primary antidepressant screens.
  • (18) Correspondingly, in the case of the histidine-peptides examined only mixtures of the cyclic isomeric compounds were isolated and structurally characterized by 1H-NMR analysis.
  • (19) In contrast to the biphasic unfolding of the wild-type nuclease, the unfolding of the mutant is represented by a single-phase reaction, indicating that the biphasic unfolding for the wild-type protein is caused by cis-trans isomerization about the prolyl peptide bond in the native state.
  • (20) In order to prepare a completely light-stable rhodopsin, we have synthesized an analog, II, of 11-cis retinal in which isomerization at the C11-C12 cis-double bond is blocked by formation of a cyclohexene ring from the C10 to C13-methyl.

Substance


Definition:

  • (n.) That which underlies all outward manifestations; substratum; the permanent subject or cause of phenomena, whether material or spiritual; that in which properties inhere; that which is real, in distinction from that which is apparent; the abiding part of any existence, in distinction from any accident; that which constitutes anything what it is; real or existing essence.
  • (n.) The most important element in any existence; the characteristic and essential components of anything; the main part; essential import; purport.
  • (n.) Body; matter; material of which a thing is made; hence, substantiality; solidity; firmness; as, the substance of which a garment is made; some textile fabrics have little substance.
  • (n.) Material possessions; estate; property; resources.
  • (n.) Same as Hypostasis, 2.
  • (v. t.) To furnish or endow with substance; to supply property to; to make rich.

Example Sentences:

  • (1) No differences between the two substances were observed with respect to side effects and general tolerability.
  • (2) Modulation of the voltage-gated K+ conductance in T-lymphocytes by substance P was examined.
  • (3) During the digestion of these radiolabeled bacteria, murine bone marrow macrophages produced low-molecular-weight substances that coeluted chromatographically with the radioactive cell wall marker.
  • (4) Intracellular localization of the labeled substance in the tumor tissue was examined autohistoradiographically.
  • (5) Substances with a leaving group at the C-3 position form unsaturated conjugated cyclic adducts and are mutagenic only in the His D3052 frameshift strains with an intact excision repair system (no urvA mutation).
  • (6) A substance with a chromatographic mobility of Rf = 0.8 on TLC plates having an intact phosphorylcholine head group was also formed but has not yet been identified.
  • (7) Serum pepsinogen 1, serum gastrin, ABO blood groups, secretor status of ABH blood group substances and behavioral factors were studied in 15 patients with duodenal ulcer and 61 their relatives affected and unaffected to duodenal ulcer.
  • (8) Agarose-albumin beads may be useful for removing protein-bound substances from the blood of patients with liver failure, intoxication with protein-bound drugs, or specific metabolic deficits.
  • (9) Urine tests in six patients with other kidney diseases and with uraemia and in seven healthy persons did not show this substance.
  • (10) Substance P, a potent vasodilating peptide, seems to be released from trigeminal nerve endings in response to nervous stimulation and is involved in the transmission of painful stimuli within the periphery.
  • (11) Regulators concerned about physician behavior and confronted by demands of nonphysicians to prescribe controlled substances may find EDT a good solution.
  • (12) These results are discussed in the light of the mode of action of the substances used.
  • (13) Most cis AB sera have anti-B activity, essentially at 4 degrees C. In saliva A and H substances are found in normal amounts but B substance is only evidenced by inhibition of autologous cells agglutination.
  • (14) We have investigated some of the factors which affect the retention times of these substances in reversed-phase HPLC on columns of 5-micron octadecylsilyl silica.
  • (15) The data indicate that adult neurons with an intrinsic ability to regenerate axons can respond to substances with neurotrophic or neurite-promoting activities in tissue cultures.
  • (16) The authors describe the role played by these substances in the pathogenesis of inflammations, their importance in the regulation of intraocular pressure and in the development of cystoid macular oedema.
  • (17) They were more irregularly curved and consisted of various substances.
  • (18) We examined 10 life areas clustered around the general categories of "substance use," "social functioning," and "emotional and interpersonal functioning."
  • (19) In certain cases, the effects of these substances are enhanced, in others, they are inhibited by compounds that were isolated from natural sources or prepared by chemical synthesis.
  • (20) The following possible explanations were discussed: a) the tested psychotropic drugs block prostaglandin receptors in the stomach; b) the test substances react with prostaglandin in the nutritive solution; c) the substances stimulate metabolic processes in the stomach wall that break down prostaglandin.

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