BUFFER SOLUTIONS

2010 ◽  
pp. 715-718
Keyword(s):  
Buffer Solutions

The Interfacial Behaviour of Mono-, Di-, and Triphosphate of Inosine at the Charged Interface

1996 ◽  
Vol 61 (11) ◽  
pp. 1600-1608
Author(s):  
Mohamed E. Ahmed
Keyword(s):  
Divalent Metal ◽  
Divalent Metal Ions ◽  
Adsorption Parameters ◽  
Buffer Solutions ◽  
Ph Values ◽  
Adsorption Equilibria ◽  
Charged Interface ◽  
Interfacial Behaviour ◽  
Phase Sensitive ◽  
Adsorption Stage

The interfacial behaviour and adsorption equilibria of mono-, di-, and triphosphate of inosine (IMP, IDP, and ITP) were carried out in different buffer solutions by phase-sensitive ac voltammetry at HMDE. The characteristic properties and adsorption parameters of dilute and compact layers were evaluated from the obtained Frumkin isotherm at different pH values. The effect of some divalent metal ions on the adsorption stage and association of the investigated compounds has been studied.

Acids, bases and buffer solutions

2018 ◽  
Author(s):  
Dennis Sherwood ◽  
Paul Dalby
Keyword(s):  
First Principles ◽  
Buffer Capacity ◽  
Unique Feature ◽  
Dissociation Constants ◽  
Equilibrium Composition ◽  
Buffer Solutions ◽  
Acid And Base ◽  
Water Ph ◽  
Acids And Bases ◽  
Conjugate Bases

Many reactions in solution involve acids and bases, and so this chapter examines these important reactions in detail. Topics covered include the ionisation of water, pH, pOH, acids and bases, conjugate acids and conjugate bases, acid and base dissociation constants, the Henderson-Hasselbalch equation, the Henderson-Hasselbalch approximation, buffer solutions and buffer capacity. A unique feature of this chapter is a ‘first principles’ analysis of how a reaction buffered at a particular pH achieves an equilibrium composition different from that of the same reaction taking place in an unbuffered solution. This introduces some concepts which are important in understanding the biochemical standard state, as required for Chapter 23.

PHYSICAL PROPERTIES OF ALKYL PYRROLES AND THEIR SALTS

1959 ◽  
Vol 37 (11) ◽  
pp. 1859-1869 ◽  
Author(s):  
R. J. Abraham ◽  
E. Bullock ◽  
S. S. Mitra
Keyword(s):  
Hydrochloric Acid ◽  
Physical Properties ◽  
Simple Function ◽  
Proton Resonance ◽  
Ultraviolet Spectra ◽  
Buffer Solutions

The structures of the ions formed by several alkyl pyrroles in hydrochloric acid are deduced from proton resonance spectra. Basicity values for three alkyl pyrroles are determined from ultraviolet spectra of their salts in buffer solutions. An attempt is made to estimate the basicity of other pyrroles from the variation of the—OD stretching frequency of methanol-d in solution in the pyrroles. Variations of the free and bonded NH frequencies of alkyl pyrroles are shown to be a simple function of the positions and number of the substituents.

scholarly journals OBSERVATIONS IMPLICATING AN EXTRACELLULAR ENZYMIC MECHANISM OF CONTROL OF BONE MORPHOGENESIS

1974 ◽  
Vol 22 (2) ◽  
pp. 88-103 ◽  
Author(s):  
MARSHALL R. URIST ◽  
HISASHI IWATA ◽  
STUART D. BOYD ◽  
PETER L. CECCOTTI ◽  
MARLYS OKADA ◽  
...  
Keyword(s):  
Chemical Reactions ◽  
Phosphate Buffer ◽  
Bone Matrix ◽  
Chemical Extraction ◽  
Ammonium Bromide ◽  
Property A ◽  
Noncollagenous Proteins ◽  
Buffer Solutions ◽  
Sequential Chemical Extraction ◽  
Chloroform Methanol

Data on physicochemical conditions leading to loss of the bone morphogenetic property of bone matrix in neutral buffer solutions support the concept of an enzymic control mechanism better than a chemical blocking reaction or denaturation. The loss is associated with release of 35S-labeled constituents and not prevented by ε-amino caproic acid, an inhibitor of cathepsins. The loss is also associated with release of 35S-cysteine-labeled protein; about 60% of the yield is sustained by the addition of only 3 mmoles/liter of iodoacetic acid. A latent period of about 12 hr, decreased by extraction of bone matrix with CaCl2, is characterized by release of protein polysaccharide and other noncollagenous proteins. Release of sialic acid from the bone matrix by neuraminidase at pH 7.4 has no effect upon bone yield. At 2°C, Tris-HCl buffer or ethylenediaminetetraacetic acid extracts noncollagenous proteins without loss of bone yield; at 37°C, pH 7.4, these solutions also activate endogenous enzymes and reduce bone yield. The component of bone matrix responsible for reduction in bone yield is separable from bone matrix by extraction with phosphate buffer, by catheptic digestion of bone matrix in acidic buffer solutions, by sequential chemical extraction of noncollagenous proteins with cold slightly acidic salt solutions or by extraction-denaturation with chloroform-methanol. Detergents neither extinguish nor denature the morphogenetic property but some solubilize or extract degradative enzymes; hexodecyl trimethyl ammonium bromide, at pH 5.0, is positively charged and extracts hydrophobic proteins, including part of the bone morphogenetic property. A special selection of sulfhydryl chemical inhibitors remarkably different from the selection inhibiting known enzymes preserves the bone morphogenetic property of bone matrix; p-chloromercuribenzoate preservation is reversible by chemical reactions with cysteine. Reduction in bone yield in phosphate buffer is not attributable to a chemical block because chloroform-methanol extraction of the agent does not restore bone yield and is not attributable to denaturation because bone yield sustained by p-chloromercuribenzoate is lost by chemical reactions with cysteine. An hypothetical insoluble bone morphogenetic protein (BMP) firmly bound to collagen is degraded by a soluble neutral proteinase (BMPase). Digestion of the hypothetical BMP occurs without loss of the 640-A electron micrographic image of bone collagen, resembles tryptic digestion and is more selective as well as physiologic in action.

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