What's the difference between chitin and shell?

Chitin


Definition:

  • (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.

Shell


Definition:

  • (n.) A hard outside covering, as of a fruit or an animal.
  • (n.) The covering, or outside part, of a nut; as, a hazelnut shell.
  • (n.) A pod.
  • (n.) The hard covering of an egg.
  • (n.) The hard calcareous or chitinous external covering of mollusks, crustaceans, and some other invertebrates. In some mollusks, as the cuttlefishes, it is internal, or concealed by the mantle. Also, the hard covering of some vertebrates, as the armadillo, the tortoise, and the like.
  • (n.) Hence, by extension, any mollusks having such a covering.
  • (n.) A hollow projectile, of various shapes, adapted for a mortar or a cannon, and containing an explosive substance, ignited with a fuse or by percussion, by means of which the projectile is burst and its fragments scattered. See Bomb.
  • (n.) The case which holds the powder, or charge of powder and shot, used with breechloading small arms.
  • (n.) Any slight hollow structure; a framework, or exterior structure, regarded as not complete or filled in; as, the shell of a house.
  • (n.) A coarse kind of coffin; also, a thin interior coffin inclosed in a more substantial one.
  • (n.) An instrument of music, as a lyre, -- the first lyre having been made, it is said, by drawing strings over a tortoise shell.
  • (n.) An engraved copper roller used in print works.
  • (n.) The husks of cacao seeds, a decoction of which is often used as a substitute for chocolate, cocoa, etc.
  • (n.) The outer frame or case of a block within which the sheaves revolve.
  • (n.) A light boat the frame of which is covered with thin wood or with paper; as, a racing shell.
  • (v. t.) To strip or break off the shell of; to take out of the shell, pod, etc.; as, to shell nuts or pease; to shell oysters.
  • (v. t.) To separate the kernels of (an ear of Indian corn, wheat, oats, etc.) from the cob, ear, or husk.
  • (v. t.) To throw shells or bombs upon or into; to bombard; as, to shell a town.
  • (v. i.) To fall off, as a shell, crust, etc.
  • (v. i.) To cast the shell, or exterior covering; to fall out of the pod or husk; as, nuts shell in falling.
  • (v. i.) To be disengaged from the ear or husk; as, wheat or rye shells in reaping.

Example Sentences:

  • (1) However, empty shells can also form independently of intact virions.
  • (2) The spikes likely correspond to VP3, a hemagglutinin, while the rest of the mass density in the outer shell represents 780 molecules of VP7, a neutralization antigen.
  • (3) Lead levels in contents and shells of eggs laid by hens dosed with all-lead shot were about twice those in eggs laid by hens dosed with lead-iron shot.
  • (4) We recommend the shell vial technique for isolation of C. burnetii.
  • (5) A significant proportion of the soluble protein of the organic matrix of mollusk shells is composed of a repeating sequence of aspartic acid separated by either glycine or serine.
  • (6) Viral particles in the cultures and the brain were of various sizes and shapes; particles ranged from 70 to over 160 nm in diameter, with a variable position of dense nucleoids and less dense core shells.
  • (7) But we sent out reconnoitres in the morning; we send out a team in advance and they get halfway down the road, maybe a quarter of the way down the road, sometimes three-quarters of the way down the road – we tried this three days in a row – and then the shelling starts and while I can’t point the finger at who starts the shelling, we get the absolute assurances from the Ukraine government that it’s not them.” Flags on all Australian government buildings will be flown at half-mast on Thursday, and an interdenominational memorial service will be held at St Patrick’s cathedral in Melbourne from 10.30am.
  • (8) Unless you are part of some Unite-esque scheme to join up as part of a grand revolutionary plan, why would you bother shelling out for a membership card?
  • (9) Serum levels of lactate dehydrogenase and alkaline phosphatase were considerably elevated in shell-less embryos.
  • (10) The cultivation of embryos in shell-less culture did not affect the normal macroscopic or histological appearance of the membrane, or the rate of proliferation of its constituent cells, as assessed by tritiated thymidine incorporation.
  • (11) Another friend’s sisters told me that the government building where all the students’ records are stored is in an area where there is frequent shelling and air strikes.
  • (12) Shell casings littered the main road, tear gas hung in the air and security forces beat local residents.
  • (13) Carmon Creek is wholly owned by Shell, which said it expected the decision to cost $2bn in its third-quarter results due to impairment, contract provision, redundancy and restructuring charges.
  • (14) A technique for efficient cytochalasin-induced enucleation was used to prepare "karyoplasts"--nuclei surrounded by a thin shell of cytoplasm and an outer cell membrane.
  • (15) The difficulty has been increased with the recent Supreme Court decision which it ruled the Alien Tort Claims Act does not apply outside of the country and dismissed a case against Royal Dutch Shell.
  • (16) We developed a shell vial cell culture assay (SVA) using a cross-reactive monoclonal antibody to the T antigen of simian virus 40 to detect BKV rapidly by indirect immunofluorescence.
  • (17) On second impacts, the GSI rose considerably because the shell and liner of the DH-151 cracked and the suspension of the "141" stretched during the first blow.
  • (18) This coincided with increases in shell thickness and shell porosity as power functions of uterine time.
  • (19) The apoferritin shell is known to assemble spontaneously from its subunits obtained at acid pH upon neutralization.
  • (20) Whereas psammomatous bodies are located within tubules in compressed residual testicular tissue arranged in a shell-like zone around the tumor mass, dystrophic calcifications and bone and cartilage tissues are identified inside the tumor.