Acids and bases

The target of this project is to construct a general and feasible procedure to determine the acidic equilibrium constants in aqueous solution at 25oC from the data of the potentiometric titration process in a rapid, simple and effective way. Then it will be applied to estimate the equilibrium constants of some new acids.

27p tunelove 10-06-2021 12 4   Download

The goals of the dissertation: Synthesizing deep eutectic solvents based on choline chloride with the compounds of 2-alkylbenzimidazole/ethylene glycol and determining their structures; using synthetic deep eutectic solvents to enrich and separate Omega-3,6,9 from waste fat in accordance with the facrories’ procedure of processing Vietnamese basa fish for export.

31p capheviahe27 23-02-2021 28 3   Download

The superabsorbent polymers based on acrylic acid have been prepared in the presence of ammonium persulfate (APS) as initiator and N,N-methylene- bis- acrylamide (MBA) as crosslinking agent. The suspension polymerisation occurred in aqueous drops dispersed in toluene and stabilised by sorbitan monooleate. Some effects on the swelling degree and size particles such as concentrations of MBA and initiator, neutralization degree (Dn) were studied. Swelling degree 405g/g, reach maximum at 85◦C and 0.09% crosslinking agent, 1.

6p 12120609 01-06-2020 11 2   Download

The mechanism of corrosion inhibition was explored and supplemented by adsorption and surface morphological studies. Quantum mechanical investigations on corrosion behaviour of compounds were also conducted and satisfying correlation was noticed between the results of corrosion measurement methods and quantum mechanical evaluations.

12p tocectocec 25-05-2020 20 2   Download

The corrosion inhibition efficiencies of two novel Schiff bases, namely (E)-3-[thiophen-2-lmethyleneamino]benzoic acid (T2YMABA) and (E)-4-(5-[(2-phenylhydrazono) methyl]thiophen-2-yl)benzoic acid (PHMT2YBA) on mild steel (MS) in 1.0M HCl solution has been investigated and compared using electrochemical impedance spectroscopy and potentiodynamic polarization analysis.

10p tocectocec 25-05-2020 19 2   Download

Pioglitazone hydrochloride (PGH) is an oral anti-hyperglycemic agent used in the treatment of type-2 diabetes mellitus. Potassium permanganate was found to oxidize PGH both in acidic and basic conditions, based on which two simple and sensitive methods were developed for its determination in bulk sample and tablets, and validated.

12p tocectocec 25-05-2020 14 2   Download

Mục tiêu bài giảng nhằm trình bày được khái niệm, thành phần cấu tạo acid nucleic, các base purin và pyrimidin; viết được công thức cấu tạo của ribose, deoxyribose; trình bày khái niệm AND, ARN cấu trúc và vai trò của nó. Để nắm rõ chi tiết các nội dung mời các bạn cùng tham khảo bài giảng.

14p dsphucmc 11-02-2019 66 7   Download

Objective of study determining diet formula for 4-breeds exotic hybrid with optimal protein level bases on balancing some essential amino acids includes: lysine, methionine and threonine in order to improve grow capacity, feed utilization efficiency and to reduce urinal and faecal nitrogen and phosphorus excretion; formulating some formulas base on the local ingredients with optimal protein and amino acids level to ensure production efficiency of exotic 4-breeds hybrid and to reduce environment pollution in pig production.

25p nguyenthiminh32 12-07-2014 66 7   Download

The design of b-glycosidases with planed substrate specificity for biotechnological application has received little attention. This is mostly a consequence of the lack of data on the molecular basis of the b-glycosidase specificity, namely data on the energy of the noncovalent interactions in the enzymetransition state complex. In an attempt to fill this gap, sitedirected mutagenesis and enzyme steady-state kinetic experiments with different substrates were conducted, using as model a digestive b-glycosidase (glycoside hydrolase family 1) from Spodoptera frugiperda (Lepidoptera) (Sfbgly50).

10p system191 01-06-2013 41 4   Download

The plant enzyme phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) shows homology to histidine ammonia-lyase (HAL) whose structure has been solved by X-ray crystallography. Based on amino-acid sequence alignment of the two enzymes, mutagenesis was performed on amino-acid residues that were identical or similar to the active site residues in HAL to gain insight into the importance of this residues in PAL for substrate binding or catalysis. We mutated the following amino-acid residues: S203, R354, Y110, Y351, N260, Q348, F400, Q488 and L138....

11p system191 01-06-2013 65 4   Download

Division of Medicinal and Natural Products Chemistry, Department of Chemistry and Department of Chemical Engineering, University of Iowa, USA; 2Department of Autoimmunology, Statens Serum Institut, Copenhagen, Denmark Synthetic peptides based on amino-acid residues 27–38 of human serum amyloid P component represent a novel type of heparin binders as they do not contain clusters of basic amino acids or other known features associated with protein or peptide heparin binding.

8p system191 01-06-2013 54 4   Download

Transglutaminase (TGase) catalyses the post-translational modification of proteins by transamidation of available glutamine residues. While several TGase genes of fish and arthropods have been cloned and appear to have similar structures to those of mammals, no homologous gene has been found in lower eukaryotes. We have cloned the acellular slime mold Physarum polycephalum TGase cDNA using RT-PCR with degenerated primers, based on the partial amino acid sequence of the purified enzyme. The cDNA contained a 2565-bp ORF encoding a 855-residue polypeptide.

10p research12 01-06-2013 48 4   Download

Strictosidine glucosidase (SG) is an enzyme that catalyses the second step in the biosynthesis of various classes of monoterpenoid indole alkaloids. Based on the comparison of cDNA sequences of SG from Catharanthus roseus and raucaffricine glucosidase (RG) from Rauvolfia serpentina, primers for RT-PCR were designed and the cDNA encoding SG was cloned from R. serpentina cell suspension cultures. The active enzyme was expressed in Escherichia coli and purified to homogeneity. Analysis of its deduced amino-acid sequence assigned the SG from R. serpentina to family 1 of glycosyl hydrolases.

10p research12 01-06-2013 43 5   Download

Y238, oneof thevery fewconservedresidues in theactive site ofD-amino acid oxidases (DAAO), was mutated to phe-nylalanine and serine in the enzyme from the yeastRhodo-torula gracilis. The mutated proteins are catalytically competent thus eliminating Tyr238 as an active-site acid/ base catalyst. Y238FandY238Smutants exhibit a threefold slower turnover on D-alanine as substrate, which can be attributed to a slower rate of product release relative to the wild-type enzyme (a change of the rate constants for sub-strate binding was also evident). ...

10p research12 29-04-2013 58 5   Download

Mammalian alcohol dehydrogenases (ADH) 3 form a com-plex enzyme system based on amino-acid sequence, func-tional properties, and gene expression pattern. At least four mouseAdhgenes are known to encode di€erent enzyme classes that share less than 60% amino-acid sequence iden-tity. Two ADH-containing and overlapping C57BL/6 bacterial arti®cial chromosome clones, RP23-393J8 and -463H24, were identi®ed in a library screen, physically mapped, and sequenced.

9p research12 29-04-2013 22 2   Download

A novel plasmid vector pSELECT-1 is described which can be used for highly efficient site-directed in vitro mutagenesis. The mutagenesis method is based on the use of single-stranded DNA and two primers, one mutagenic primer and a second correction primer which corrects a defect in the ampicillin resistance gene on the vector and reverts the vector to ampicillin resistance. Using T4 DNA polymerase and T4 DNA ligase the two primers are physically linked on the template. The non-mutant DNA strand is selected against by growth in the presence of ampicillin.

5p zingzing09 24-04-2013 60 5   Download

A new approach of predicting structural classes of protein domain sequences is presented in this paper. Besides the amino acid composition, the composition of several dipeptides, tripeptides, tetrapeptides, pentapeptides and hexapeptides are taken into account based on the step-wise discriminant analysis. The result of jackknife test shows that this new approach can lead to higher pre-dictive sensitivityand specificityfor reduced sequence similaritydatasets.

7p research12 23-04-2013 33 3   Download

An arti®cial peroxidase-like hemoprotein has been obtained by associating a monoclonal antibody, 13G10, and its iron(III)±a,a,a,b-meso-tetrakis(ortho-carboxyphenyl)por-phyrin [Fe(ToCPP)] hapten. In this antibody, about two-thirds of the porphyrinmoiety is inserted in the binding site, its ortho-COOH substituents being recognized by amino-acids of the protein, and a carboxylic acid side chain of the protein acts as a general acid base catalyst in the heterolytic cleavage of the O±O bond of H2O2, but no amino-acid res-idue is actingas anaxial ligandof the iron....

11p research12 23-04-2013 35 2   Download

Protein molecular modelling and ligand docking were employed for the design of anthraquinone galactosyl-bio-mimetic dye ligands (galactosyl-mimodyes) for the target enzyme galactose dehydrogenase (GaDH). Using appro-priate modelling methodology, a GaDH model was build based on a glucose-fructose oxidoreductase (GFO) protein template.

15p tumor12 22-04-2013 46 2   Download

Glutamate decarboxylase is a pyridoxal 5¢-phosphate-dependent enzyme responsible for the irreversiblea-decar-boxylation of glutamate to yield 4-aminobutyrate. In Escherichia coli, as well as in other pathogenic and non-pathogenic enteric bacteria, this enzyme is a structural component of the glutamate-based acid resistance system responsible for cell survival in extremely acidic conditions (pH

8p tumor12 22-04-2013 31 3   Download