What's the difference between isomer and structure?

Isomer


Definition:

  • (n.) A body or compound which is isomeric with another body or compound; a member of an isomeric series.

Example Sentences:

  • (1) An unsaturated fatty acid auxotroph of Escherichia coli was grown with a series of cis-octadecenoate isomers in which the location of the double bond varied from positions 3 to 17.
  • (2) Fluorination with [18F]acetylhypofluorite yields 6-[18F]fluoro-L-dopa with 95% radiochemical purity; fluorination of the same substrate with [18F]F2 yields a mixture of all three structural isomers in a ratio of 70:16:14 for 6-, 5-, and 2-fluoro compounds.
  • (3) The cis isomer was retained longer in liver, particularly in mitochondria, but had low retention in that portion of the endoplasmic reticulum isolated as the rough membrane fraction.
  • (4) The purity and configuration of each isomer of the free acid and N-chloroacetylated derivative were ascertained by: (a) paper chromatography in five solvent systems, (b) elemental analysis, (c) Van Slyke nitrous acid determination of alpha-carbonyl carbon, and (d) Van Slyke ninhydrin determination of alpha-carbonyl carbon, and (e) optical rotation.
  • (5) The stronger negative potentials may weaken electrostatic receptor interactions and, thereby, cause the trans(E)-isomers to be less active than cis(Z)-isomers.
  • (6) The identity of each of the three forms was determined by carboxymethylation of the free cysteines in each isomer with [3H]iodoacetic acid followed by determination of the labelled cysteines by tryptic peptide mapping.
  • (7) In contrast to the enantiomeric discrimination observed with racemic amine, the individual isomers were metabolized at approximately the same rate.
  • (8) To further assess different binding behavior of these two isomers, association rate was measured.
  • (9) None of the 3 beta- or 5 beta-isomers had any effect.
  • (10) Isomers and epimers of glucose influence insulin and cAMP in a parallel fashion as do sulfonylurea compounds (tolbutamide and glibenclamide).
  • (11) Bioaccumulation experiments were performed on the hexachlorocyclohexane isomers alpha-HCH, beta-HCH, gamma-HCH and delta-HCH, testing them simultaneously.
  • (12) Although serum total LDH activity was not altered, the LD5 isoenzyme was proportionately higher in the HCH isomers treated animals.
  • (13) Racemic verapamil and the L- and D-isomer increased cellular vincristine accumulation to the same extent.
  • (14) The hypothesis that opiate agonism requires an N substituent in the axial position does not appear to be consistent with the increased potency of beta isomers in which axial N substituents are thermodynamically more unstable.
  • (15) In the case of adducts with the diol-epoxides of benzo[c]phenanthrene, the energetically most favored structures are isomers with significant biological activity.
  • (16) Liver regeneration was stimulated in male rats with two-thirds of the liver removed by feeding a basal diet supplemented with acetaminophen (0.35-1.5%; weight basis), 2-acetamidophenol (1.0%) and acetophenetidin (1.0%) over a period of 10 days po, but was in the control range with the m-isomer, 3-acetamidophenol (1.0%), N-butyryl-p-aminophenol (1.0%), o-, m- and p-aminophenols (0.50%) and 4-acetamidothiophenol.
  • (17) However, exposure of the cells to either of the two isomers of azoxy-procarbazine led to significant DNA damage and cytotoxicity.
  • (18) 1"-Oxobufuralol (3) was reduced with a complex of (2S)-(-)-2-amino-3-methyl-1,1-diphenylbutan-1-ol and borane, yielding 2, which had a 95:5 ratio of the possible 1"R and 1"S isomers as determined by HPLC.
  • (19) As the two signals had the same intensities, it was suggested that equivalent amounts of cis and trans isomers of the alkenylmether were formed.
  • (20) The most important recent work has concerned the different anticoagulant potencies and metabolic pathways of the optical isomers of some of these drugs.

Structure


Definition:

  • (n.) The act of building; the practice of erecting buildings; construction.
  • (n.) Manner of building; form; make; construction.
  • (n.) Arrangement of parts, of organs, or of constituent particles, in a substance or body; as, the structure of a rock or a mineral; the structure of a sentence.
  • (n.) Manner of organization; the arrangement of the different tissues or parts of animal and vegetable organisms; as, organic structure, or the structure of animals and plants; cellular structure.
  • (n.) That which is built; a building; esp., a building of some size or magnificence; an edifice.

Example Sentences:

  • (1) The findings indicate that there is still a significant incongruence between the value structure of most family practice units and that of their institutions but that many family practice units are beginning to achieve parity of promotion and tenure with other departments in their institutions.
  • (2) The influence of the various concepts for the induction of lateral structure formation in lipid membranes on integral functional units like ionophores is demonstrated by analysing the single channel current fluctuations of gramicidin in bimolecular lipid membranes.
  • (3) We have determined the genomic structure of the fosB gene and shown that it consists of 4 exons and 3 introns at positions also found in the c-fos gene.
  • (4) 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.
  • (5) The fine structure of neurofibrillary tangles in the hippocampal gyrus, substantia nigra, pontine nuclei and locus coeruleus of the brain was postmortem studied in a case of progressive supranuclear palsy.
  • (6) 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.
  • (7) It has been generally believed that the ligand-binding of steroid hormone receptors triggers an allosteric change in receptor structure, manifested by an increased affinity of the receptor for DNA in vitro and nuclear target elements in vivo, as monitored by nuclear translocation.
  • (8) Immunocytochemistry was used to visualize cytoskeletal structures and to assay selective disruption of neurofilaments by acrylamide.
  • (9) The quaternary structure of ribonucleotide reductase of Escherichia coli was investigated, with the use of purified B1 and B2 proteins and bifunctional cross-linking agents.
  • (10) Structural peculiarities in tubulin polymorphism are considered.
  • (11) We report a series of experiments designed to determine if agents and conditions that have been reported to alter sodium reabsorption, Na-K-ATPase activity or cellular structure in the rat distal nephron might also regulate the density or affinity of binding of 3H-metolazone to the putative thiazide receptor in the distal nephron.
  • (12) It is likely that trunk mobility is necessary to maintain integrity of SI joint and that absence of such mobility compromises SI joint structure in many paraplegics.
  • (13) Fluorination with [18F]acetylhypofluorite yields 6-[18F]fluoro-L-dopa with 95% radiochemical purity; fluorination of the same substrate with [18F]F2 yields a mixture of all three structural isomers in a ratio of 70:16:14 for 6-, 5-, and 2-fluoro compounds.
  • (14) But the wounding charge in 2010 has become Brown's creation of a structural hole in the budget, more serious than the cyclical hit which the recession made in tax receipts, at least 4% of GDP.
  • (15) The aetiological factors concerned in the production of paraumbilical and epigastric hernias have been reviewed along structural--functional lines.
  • (16) The disassembly of the synthetase complex is consistent with the structural model of a heterotypic multienzyme complex and suggests that the complex formation is due to the specific intermolecular interactions among the synthetases.
  • (17) In addition to the phase diagrams reported here for these two binary mixtures, a brief theoretical discussion is given of other possible phase diagrams that may be appropriate to other lipid mixtures with particular consideration given to the problem of crystalline phases of different structures and the possible occurrence of second-order phase transitions in these mixtures.
  • (18) The structures of 1 and 2 were established mainly on the basis of nmr spectroscopic data.
  • (19) Determination of the primary structure for factor V has provided the basis for examination of structure-function relationships.
  • (20) Aside from these characteristic findings of HCC, it was important to reveal the following features for the diagnosis of well differentiated type of small HCC: variable thickening or distortion of trabecular structure in association with nuclear crowding, acinar formation, selective cytoplasmic accumulation of Mallory bodies, nuclear abnormalities consisting of thickening of nucleolus, hepatic cords in close contact with bile ducts or blood vessels, and hepatocytes growing in a fibrous environment.