(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.
Polybasic
Definition:
(a.) Capable of neutralizing, or of combining with, several molecules of a monacid base; having several hydrogen atoms capable of being replaced by basic radicals; -- said of certain acids; as, sulphuric acid is polybasic.
Example Sentences:
(1) The polypeptide does not, however, have a deswelling effect on the tissue; the ultimate reduction in swelling is influenced by the absolute amount of polybase which enters the tissue during the swelling process.
(2) Only casein kinase-2 and a spleen tyrosine protein kinase (TPK-III) proved effective, their phosphorylation efficiency being dramatically enhanced by histones and other polybasic peptides while being depressed by 50 microM Ca2+.
(3) Within the hypervariable domain of p21K-ras(B), which is not palmitoylated, we have identified a novel plasma membrane targeting signal consisting of a polybasic domain that also acts in combination with the CAAX motif.
(4) The polybasic acids trypan blue and its analogue trypan red, bromphenol blue and its analogue bromthymol blue at concentrations of 0.22 mM and ethylenediaminetetra-acetic acid (EDTA) at a concentration of 1 mM are strong inhibitors of the enzyme.3.
(5) Mutational analysis of p21ras has shown that plasma membrane targeting requires the combination of a CAAX motif with a polybasic domain of six lysine residues or a nearby palmitoylation site.
(6) A method for the isolation of vacuoles based on polybase induced lysis of protoplasts of the cell wall deficient Neurospora crassa slime variant is described.
(7) Plasma membrane targeting of p21K-ras(B) requires a CAAX motif and a polybasic domain.
(8) The swelling kinetics of polybasic gels consisting of copolymers of methyl methacrylate and dimethylaminoethyl methacrylate are studied in solutions at various acidic pH values, with monoacidic derivatives of acetic acid added as buffers.
(9) Polybasic acids affording insoluble salts were evaluated for their ability to form drug:acid:metal complexes with the polyvalent metal ions, Zn++, Al+++, Mg++ and Ca++.
(10) Modification of BHV tissue was obtained by covalently binding protamine sulfate, a polybasic peptide, via glutaraldehyde.
(11) Potassium chloride in high concentrations and calcium chloride in low concentrations inhibited polybase induced lysis of spheroplasts by preventing or even reversing the polybase adsorption.
(12) Profilin with one covalently attached actin CNBr peptide was purified by gel filtration followed by gel electrophoresis and electroblotting on polybase-coated glass-fiber membranes.
(13) Modification of BHV tissue was obtained by covalently binding protamine sulfate, a polybasic peptide, via formaldehyde and subsequent glutaraldehyde tissue crosslinking.
(14) With labeled proteins used as models, it is found that the transport proceeds at very low rates, requires little energy, and is markedly enhanced by polybasic compounds.
(15) The polybasic macromolecules DEAE-dextran (diethylaminoethyl-dextran, molecular weight 500000) and poly-DL-lysine (molecular weight 30000-70000) were absorbed with a high affinity by spheroplasts of Candida utilis and subsequently, induced lysis.
(16) The differences in accumulation levels of Mn2+ and Sr2+ attained after prolonged incubation are completely abolished in cells of which the plasmamembrane has been permeabilized with the polybase DEAE-dextran under isotonic conditions.
(17) Adsorption of polybases was rapidly completed even at 0 degrees C; however, with small doses, lysis was poor at 0-12 degrees C and extensive at temperatures above 12 degrees C. This permitted the completion of adsorption before initiating lysis.
(18) The results indicate that the phosphorylated form of PGKARKKSSC-geranylgeranyl stoichiometrically interacts with smg p21 GDS, that the presence of the geranylgeranyl moiety is essential for, but not sufficient for, the smg p21 GDS action, and that the presence of the methyl moiety, removal of the three C-terminal amino acids, and the presence of the polybasic amino acids also affect the smg p21 GDS action.
(19) Vacuoles isolated from polybase lysed spheroplasts still contained large pools of soluble amino acids, and their ability to transport arginine specifically is a further indication of their functional integrity.
(20) It is proposed that the cationic C3a molecule activates rat mast cells in a secretory and nonlytic manner by a nonspecific mechanism similar to that of other polybasic compounds.