(n.) A white amorphous horny substance forming the harder part of the outer integument of insects, crustacea, and various other invertebrates; entomolin.
Example Sentences:
(1) The effect of O-(carboxymethyl)chitins (CM-chitins) on the activation of mouse-peritoneal macrophages in vivo and their mitogenic activity on mouse spleen-cells were investigated.
(2) The pH activity profile, cofactor requirements, and kinetic parameters of the endogenously activated chitin synthase were identical to those of the trypsin-activated enzyme in protoplast membranes.
(3) Results obtained from isotopic dilution experiments are consistent with the operation of the chitin pathway as it has been established in fungal preparations.
(4) The significance of these results is discussed in connection with the mechanism of chitin synthesis and cell wall morphogenesis in S. cerevisiae.
(5) Here we show that the nodulation genes of this bacterium determine the production of a large family of Nod-factors which are N-acylated chitin pentamers carrying a variety of substituents.
(6) In a permeabilized-cell assay, Oct-Gln-UPOC had a 10-fold-lower inhibitory activity toward chitin synthetase than did the Oct-Lys-UPOC analog.
(7) The preparation yielded an apparent Km of 3.9 mg chitin ml-1 [17.6 mM-N-acetylglucosamine (GlcNAc) equivalents] and V of 2.3 nmol GlcNAc formed min-1 (mg protein)-1.
(8) In the case of the [14C]chitin synthesized, which does not show inhibition by alpha factor, the lowering of the specific activity of the precursor is exactly compensated for by an increased rate of chitin synthesis caused by alpha factor.
(9) Chitin derivatives are also used in things like contact lens, surgical stitches and artificial skin.
(10) The inhibitor was effective against crude or purified (chitosome) preparations of chitin synthetase.
(11) After 3 h incubation with tioconazole, 1 microgram ml-1, the incorporation of the radiolabelled glucose into chitin of intact cells and regenerating spheroplasts of C. albicans was inhibited by 43% and 30%, respectively.
(12) Electron microscopy has revealed that chitin from a representative selection of insect orders (plus one crustacean and one arachnid) is localized in crystallites about 2.8 nm across.
(13) When dividing cells of Saccharomyces cerevisiae were exposed to the polysaccharide-binding dye Congo red, the walls and septa became sites of chitin accumulation.
(14) Partially O-hydroxyethylated chitin (glycol chitin) was used as a substrate in the purification and characterization of this enzyme.
(15) In view of the small molecular size and high lipid solubility of methyl mercury and the lipophilic properties of the chitin-protein exoskeleton of the lobster, it is likely that significant uptake directly from the water as well as storage of absorbed methyl mercury occurred in the tail region.
(16) This confirmed that S. pombe cell wall is devoid of chitin.
(17) Adjuvant activity of chitin derivatives was examined in guinea-pigs and mice.
(18) DFB inhibits chitin synthesis and growth of imaginal epidermis in insects and suppresses melanogenesis and uptake of nucleosides in mouse melanoma cells, but the means of cell growth regulation and the role of metabolism of DFB in such regulation have not been established.
(19) These microfibers have a diameter of 80 A and may consist of chitin crystallites surrounded by a matrix coat.
(20) Chemical analysis of adult females of Onchocerca gibsoni gave estimated chitin contents of 200-500 micrograms (g dry weight)-1.
Insect
Definition:
(n.) One of the Insecta; esp., one of the Hexapoda. See Insecta.
(n.) Any air-breathing arthropod, as a spider or scorpion.
(n.) Any small crustacean. In a wider sense, the word is often loosely applied to various small invertebrates.
(n.) Fig.: Any small, trivial, or contemptible person or thing.
(a.) Of or pertaining to an insect or insects.
(a.) Like an insect; small; mean; ephemeral.
Example Sentences:
(1) Employed method of observation gave quantitative information about the influence of odours on ratios of basic predeterminate activities, insect distribution pattern and their tendency to choose zones with an odour.
(2) Suspensions of isolated insect flight muscle thick filaments were embedded in layers of vitreous ice and visualized in the electron microscope under liquid nitrogen conditions.
(3) After treatment of larvae of instar 1 at preimago stages about 77% of the insects died.
(4) The presence of potential insect vectors and the occurrence of clinical signs are indications of active transmissions.
(5) Spectrophotometric tests for the presence of a lysozyme-like principle in the serum also revealed similar trends with a significant loss of enzyme activity in 2,4,5-T-treated insects.
(6) Radiation inactivation and simple target theory were employed to determine the molecular weight of an insect CNS alpha-bungarotoxin binding component in the presence and absence of a cross-linking reagent, dimethyl suberimate.
(7) Bacillus thuringiensis subspecies kurstaki (Btk) and subspecies berliner (Btb) both produce lepidopteran-specific larvicidal protoxins with different activities against the same insect species.
(8) Phyla as diverse as insects, birds, and mammals possess distinct HRAS and KRAS sequences, suggesting that these genes are essential to metazoa.
(9) Compounds identified as sex attractant pheromones in a number of phytophagous insects were found in a variety of host plants.
(10) casseliflavus from 43.5% of members of the 37 taxa of insects.
(11) This is the first demonstration of a 2-hydroxylated carotenoid in an insect.
(12) Among the most highly expressing transformed plants for each gene, the plants with the partially modified cryIA(b) gene had a 10-fold higher level of insect control protein and plants with the fully modified cryIA(b) had a 100-fold higher level of CryIA(b) protein compared with the wild-type gene.
(13) Expression of these two cDNAs in insect cells by recombinant baculovirus revealed that the alpha 1 subunit, after noncovalent association with the beta subunit, has the same potency as the native alpha subunit purified from the pituitary.
(14) We have examined the organization of the repeated and single copy DNA sequences in the genomes of two insects, the honeybee (Apis mellifera) and the housefly (Musca domestica).
(15) But pipeline opponents say that by moving beetles from the Nebraska sandhills and mowing miles of grass where the insects once lived, TransCanada has illegally begun construction on the project.
(16) The complete amino acid sequence of 147 residues was determined automatically for a major dimeric component (CTT VI) of the insect larva Chironomus thummi thummi (Diptera).
(17) Peptides B and C are isoforms of a 43-residue peptide which contains 6 cysteines and shows significant sequence homology to insect defensins, initially reported from dipteran insects.
(18) The results suggested that allergenic cross-reactivity between some fly species exists, and may extend to taxonomically unrelated insect species.
(19) The species studied were Triatoma infestans, Triatoma brasiliensis, Triatoma vitticeps, Triatoma pseudomaculata, Rhodnius prolixus and Panstrongylus megistus, and 34 to 348 insects were studied in each group (average, 190).
(20) There is evidence that they might predate on our native shrimps, on our insect larvae, possibly fish eggs.