Dissociation constant biological buffers

The Henderson-Hasselbalch equation was developed independently by the Ameriean biological chemist L. J. Henderson and the Swedish physiologist K. A. Hasselbaleh, for relating the pH to the bicarbonate buffer system of the blood (see below). In its general form, the Henderson-Hasselbalch equation is a useful expression for buffer caleulations. It can be derived from the equilibrium constant expression for a dissociation reaction of the general weak acid (HA) in Equation (1.3) ... 

Due to the counterion localization, conformations of branched macroions that comprise strongly dissociating groups (charge is quenched) are almost insensitive to the addition of salt, up to relatively high salt concentrations. The ability of a branched polyion to maintain a virtually constant ionic strength in its interior is of special interest for potential applications, where a controlled (buffered) microenvironment is essential (e.g., colloidal bionanoreactors, smart nanocontainers for biologically active molecules, etc.). 

One of the major applications of pM buffers is in maintaining concentrations of necessary metal ions in biological nutrient media at essentially constant levels. As free metal ions are removed from the system, perhaps by hydrolysis or by incorporation into metalloenzymes, they are replenished by the reversible dissociation from a reservoir of metal complex. Among the first complexing agents used in this way were citrate and tartrate ions, but more recently aminopoly-carboxylic acids such as ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA) and nitrilotriacetic acid (NTA) have become the chelating agents... 

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