Biochemical Buffers

Buffers are often added to maintain a constant pH in biochemical research6 and naturally occurring buffer systems within body fluids and cells are very important (Box 6-A). Among the most important natural buffers are the proteins themselves, with the imidazole groups of histidine side chains providing much of the buffering capacity of cells around pH 7 (Figs. 3-1 and 3-2). Table 3-1 lists some useful biochemical buffers and their pKa values. Here are a few... 

Salt should be present in a sample only if it is an absolute requirement. Carrier ampholytes contribute to the ionic strength of the solution and can help to counteract a lack of salts in a sample. Small samples (1 to 10 /zL) in typical biochemical buffers are usually tolerated, but better results can be obtained with solutions in deionized water, 2% ampholytes, or 1% glycine. 

To understand the importance of pH and biochemical buffers in physiological regulation and be able to perform related calculations. 

Buffered solutions should be prepared under sterile conditions, and stored after ultrafiltration. Many biochemical buffer systems are excellent growth media for bacteria. 

Trizma. [Sigma Prodotti Chimici] Tris(hydioxymethyl)aniinomethane biochemical buffer. 

A list of commonly used biochemical buffers and their interaction with some metal ions have been summarised by Good and Izawa (1972). 

Acid and Base Form of Some Useful Biochemical Buffers... 

Alkaline pH, that is essential for the saponification process, can be realized through biochemical buffer systems, predominately aminoalkanoles. 

Although Tris has been a major biochemical buffer for many years, partly because it is relatively inexpensive and... 

Within minutes, Brianna determines that the patient s blood pH is 7.30 and the partial pressure of CO2 gas is above the desired level. Blood pH is typically in the range of 7.35-7.45, and a value less than 7.35 indicates a state of acidosis. Respiratory acidosis occurs due to an increase in the partial pressure of CO2 gas in the bloodstream which prevents the biochemical buffers in blood from making a change in the pH. 

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