(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.
Exoskeleton
Definition:
(n.) The hardened parts of the external integument of an animal, including hair, feathers, nails, horns, scales, etc.,as well as the armor of armadillos and many reptiles, and the shells or hardened integument of numerous invertebrates; external skeleton; dermoskeleton.
Example Sentences:
(1) King crabs (Family Lithodidae) are among the world's largest arthropods, having a crab-like morphology and a strongly calcified exoskeleton.
(2) "It confirms our prediction that we are going to elicit a sensation that the exoskeleton is an extension of their body," Nicolelis said.
(3) These principles may look tricksy or artificial when described rather than experienced but are not, says Catton, an "exoskeleton" – rather they are entirely bound up with the ideas of the book.
(4) 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.
(5) Freed of the need to wave their tentacles around to hunt for food, the coral can devote more energy to secreting the mineral calcium carbonate, from which they form a stony exoskeleton.
(6) The exoskeleton is fitted with multiple gyros to stop it falling over during the balancing act of bipedal walking.
(7) Replicas of porous hydroxyapatite that had been obtained after hydrothermal conversion of the calcium carbonate exoskeleton of coral (genus Goniopora) were implanted intramuscularly in twenty-four adult male baboons (Papio ursinus).
(8) Wild P. monodon exoskeleton contained on average 26.3 ppm total carotenoid; normally pigmented farmed shrimp had a similar concentration (25.3 ppm).
(9) Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues.
(10) Yet Ekso is notable not only for its technology and the price tag (£100,000 for the exoskeleton which it hopes to lower to £50,000 within the next two years), but its ambitious plans.
(11) The robotics work was coordinated by Gordon Cheng at the Technical University in Munich, and French researchers built the exoskeleton.
(12) Spores of T. cylindrosporum are able to adhere to the exoskeleton and penetrate it.
(13) Solubilization of the exoskeleton occurs around an area of the elaborately infolded surface membrane at the anterior of the organism.
(14) If the sight of Robert Downey Jr summoning his Iron Man accessories from across a room gave you a taste for having your own powered exoskeleton, your wish may soon be granted.
(15) Soldiers wearing bionic exoskeletons leap over trucks, firing bizarre “directed energy” weapons that send out fatal force waves.
(16) In an age when Tony Stark's exoskeleton tops the box-office charts in Avengers Assemble, and Pistorius competes in both the Olympics and Paralympics, Ekso thinks there's a demand for robotic suits that not only aid disabled people, but enhance the abilities of everyone.
(17) Two bursts of exoskeleton hardening and growth of the poison gland apparatus corresponds with a transitional period in the behavioral development of workers and finally with their development into nest defenders and foragers.
(18) We realized however, that these studies may not have fully appreciated the structure of the insect exoskeleton.
(19) But this is just one of the stories emerging: see also 3Ders' piece on a four-year old called Hannah , with a condition called arthrogryposis that limits her ability to lift her arms unaided, but who now has a Wilmington Robotic Exoskeleton (WREX for short) to help, made using 3D printing.
(20) Campaniform sensilla are proprioceptive mechanoreceptors associated with the exoskeleton.