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Buffer capacity rises to a local maximum at pH = pK a. The height of this peak depends on the value of pK a. Buffer capacity is negligible when the concentration [HA] of buffering agent is very small and increases with increasing concentration of the buffering agent. [3] Some authors show only this region in graphs of buffer capacity. [2]
Solubility: For ease in handling and because biological systems are in aqueous systems, good solubility in water was required. Low solubility in nonpolar solvents (fats, oils, and organic solvents) was also considered beneficial, as this would tend to prevent the buffer compound from accumulating in nonpolar compartments in biological systems ...
Proteins of the erythrocyte membrane separated by SDS-PAGE according to their molecular masses. SDS-PAGE (sodium dodecyl sulfate–polyacrylamide gel electrophoresis) is a discontinuous electrophoretic system developed by Ulrich K. Laemmli which is commonly used as a method to separate proteins with molecular masses between 5 and 250 kDa.
MOPS (3-(N-morpholino)propanesulfonic acid) is a buffer introduced in the 1960s, one of the twenty Good's buffers. It is a structural analog to MES, [1] and like MES, its structure contains a morpholine ring. HEPES is a similar pH buffering compound that contains a piperazine ring.
The useful buffer range for tris (pH 7–9) coincides with the physiological pH typical of most living organisms. This, and its low cost, make tris one of the most common buffers in the biology/biochemistry laboratory. Tris is also used as a primary standard to standardize acid solutions for chemical analysis.
MES is used as a buffering agent in biology and biochemistry. It has pK a value of 6.15 at 20 °C. The pH (and pK a at ionic strength I≠0) of the buffer solution changes with concentration and temperature, and this effect may be predicted using online calculators. [2] MES is highly soluble in water. The melting point is approx. 300 °C.
Intracellular pH is typically lower than extracellular pH due to lower concentrations of HCO 3 −. [9] A rise of extracellular (e.g., serum) partial pressure of carbon dioxide (pCO 2) above 45 mmHg leads to formation of carbonic acid, which causes a decrease of pH i as it dissociates: [10]
Desalting and buffer exchange are two of the most common gel filtration chromatography applications, and they can be performed using the same resin. Desalting and buffer exchange both entail recovering the components of a sample in whatever buffer is used to pre-equilibrate the small, porous polymer beads (resin).