(a.) Sour, sharp, or biting to the taste; tart; having the taste of vinegar: as, acid fruits or liquors. Also fig.: Sour-tempered.
(a.) Of or pertaining to an acid; as, acid reaction.
(n.) A sour substance.
(n.) One of a class of compounds, generally but not always distinguished by their sour taste, solubility in water, and reddening of vegetable blue or violet colors. They are also characterized by the power of destroying the distinctive properties of alkalies or bases, combining with them to form salts, at the same time losing their own peculiar properties. They all contain hydrogen, united with a more negative element or radical, either alone, or more generally with oxygen, and take their names from this negative element or radical. Those which contain no oxygen are sometimes called hydracids in distinction from the others which are called oxygen acids or oxacids.
Example Sentences:
(1) The amino acid sequence deduced from the nucleotide sequence contained both amino- and carboxyl-terminal sequences.
(2) F(420) is photolabile aerobically in neutral and basic solutions, whereas the acid-stable chromophore is not photolabile under these conditions.
(3) The high amino acid levels in the cells suggest that these cells act as inter-organ transporters and reservoirs of amino acids, they have a different role in their handling and metabolism from those of mammals.
(4) If ascorbic acid was omitted from the culture medium, the extensive new connective tissue matrix was not produced.
(5) The interaction of the antibody with both the bacterial and the tissue derived polysialic acids suggests that the conformational epitope critical for the interaction is formed by both classes of compounds.
(6) Arachidic acid was without effect, while linoleic acid and linolenic acid were (on a concentration basis) at least 5-times less active than arachidonic acid.
(7) 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.
(8) The ability of azelastine to influence antigen-induced contractile responses (Schultz-Dale phenomenon) in isolated tracheal segments of the guinea-pig was investigated and compared with selected antiallergic drugs and inhibitors of arachidonic acid metabolism.
(9) After 4 to 6 hours of recirculation, accumulation of vasoactive amine, 5-hydroxytryptamine, its major metabolite, 5-hydroxyindole acetic acid, and its precursor amino acid, tryptophan were detected.
(10) Spectrophotometric determination of the sulfhydryl content in the animal tissue before (control) and after using 6,6'-Dithiodinicotinic acid is applied.
(11) This death is also dependent on the presence of chloride and is prevented with the non-selective EAA antagonist, kynurenic acid, but is not prevented by QA.
(12) However, four of ten young adult outer arm (relatively sun-exposed) and one of ten young adult inner arm (relatively sun-protected) fibroblasts lines increased their saturation density in response to retinoic acid.
(13) Microionophoretically applied excitatory amino acids induced firing of extracellularly recorded single units in a tissue slice preparation of the mouse cochlear nucleus, and the similarly applied antagonist 2-amino-5-phosphonovalerate (2APV) was demonstrated to be a selective N-methyl-D-aspartate (NMDA) receptor antagonist.
(14) The LD50 of the following metal-binding chelating drugs, EDTA, diethylenetriaminepentaacetic acid (DTPA), hydroxyethylenediaminetriacetic acid (HEDTA), cyclohexanediaminotetraacetic acid (CDTA) and triethylenetetraminehexaacetic acid (TTHA) was evaluated in terms of mortality in rats after intraperitoneal administration and was found to be in the order: CDTA greater than EDTA greater than DTPA greater than TTHA greater than HEDTA.
(15) Estimations of the degree of incorporation of 14C from the radioactive labeled carbohydrate into the glycerol and fatty acid moieties were carried out.
(16) The second amino acid residue influences not only the rate of reaction but also the extent of formation of the product of the Amadori rearrangement, the ketoamine.
(17) Leumorphin is a 29-amino-acid peptide derived from preproenkephalin B. Intracerebroventricular (i.c.v.)
(18) Hepatic lymph flow increased only after ethacrynic acid and mannitol administration.
(19) The subcellular distribution of sialyltransferase and its product of action, sialic acid, was investigated in the undifferentiated cells of the rat intestinal crypts and compared with the pattern observed in the differentiated cells present in the surface epithelium.
(20) A phytochemical investigation of an ethanolic extract of the whole plant of Echites hirsuta (Apocynaceae) resulted in the isolation and identification of the flavonoids naringenin, aromadendrin (dihydrokaempferol), and kaempferol; the coumarin fraxetin; the triterpene ursolic acid; and the sterol glycoside sitosteryl glucoside.
Amphoteric
Definition:
(a.) Partly one and partly the other; neither acid nor alkaline; neutral.
Example Sentences:
(1) A series of comparative experiments were undertaken by us in order to study the influence of anionic, nonionic and amphoteric detergents on the production of ascitic fluid from macerates of Yoshida sarcoma and fibrosarcoma BUSP.
(2) Steroid sulfatase of human placenta has been solubilized by treatment of the microsomal fraction with an amphoteric surface active agent, Miranol H2M and ultrasound.
(3) Feldamycin, C17H25N7O5, is an amphoteric compound which inhibits a variety of bacteria in vitro but is found to be ineffective in the treatment of experimental bacterial infections in mice.
(4) Most of the problems connected with the use of the Immobiline chemicals (a set of six, non-amphoteric, acrylamido buffers having pK values in the pH 3.5-9.5 interval) can be attributed to the alkaline species (with pK values 6.2, 7.0, 8.5 and 9.3).
(5) Both amphoteric and quaternary ammonium adapted organisms showed changes in their fatty acid profiles consistent with outer membrane modification but the changes were different in each case.
(6) A protein liquid membrane composed of coacervated alpha-elastin, a chemical fragmentation product of the biological elastic fiber protein, functioned as an amphoteric liquid ion-exchange membrane.
(7) In mixed-bed, carrier ampholyte-Immobiline gels, a primary, insolubilized pH gradient is admixed with a secondary, soluble pH gradient generated by amphoteric buffers.
(8) The antibiotic was purified by a combination of ion-exchange and adsorption chromatography based on its amphoteric water-soluble characteristics.
(9) The chemical analysis of 3-methoxytyramine, normetanephrine, and metanephrine in tissues, blood, and cerebrospinal fluid is complicated by the low levels in which they occur and the amphoteric nature of the functional groups, which hampers their isolation from aqueous media.
(10) Capacity-limited ester hydrolysis in the liver was the main metabolic pathway, yielding a single amphoteric metabolite.
(11) DHEC exercises a vasoregulating amphoteric action which depends on the initial tonus: it is hypotensive in hypertensive and normotensive animals but it is hypertensive in hypotensive animals.
(12) The mass spectrometric study of these components by classical ionization techniques such as electron impact, chemical ionization or field desorption require a prior chemical derivatization because of their amphoteric properties, their low volatility and low thermostability.
(13) These two antibiotics are amphoteric in nature, soluble in particular solvents such as dimethylsulfoxide, dimethylformamide and alkaline water, and show typical infrared absorptions of peptide.
(14) Cationogenic, anionogenic, non-ionogenic and amphoteric tensides were more or less effective in inactivating horseradish peroxidase.
(15) Amphoteric, isoelectric agarose membranes, as devised by Martin and Hampson [Martin, A.J.P.
(16) The results have been explained in terms of the ion exchange theory by postulating that the membrane has fixed amphoteric groups.
(17) This new detection method is unique concerning direct measurements of charge densities and isoelectric points of amphoteric macromolecules adsorbed in the membrane.
(18) The radioactivity was separated by ion-exchange chromatography into two major fractions: one acidic, the other amphoteric.
(19) Adaptation to both biocides resulted in cross resistance to biguanides but whereas quaternary adapted cells were resistant to a range of quaternary ammonium compounds, the amphoteric adapted organisms were not.
(20) Minimum inhibitory concentrations and the effective period for cidal concentrations of an amphoteric surfactant mixture (C31G) were determined on 13 microorganisms (common bacteria, strains ATCC, and fungi) by microtiter dilution procedure.