The of import use of buffer solution was showed through comparing of the alteration of pH utilizing phosphate buffer and distilled H2O when acid and basic solution was added. A phosphate buffer was foremost produced by blending 2.652 g of KH2PO4 and 5.307 g of K2HPO4. The initial pH of the solution was measured at 7.00 which is 5.41 % lower than the theoretical pH. When 25ml of the buffer was used and 10.0ml of 0.100M HCl and 0.100M NaOH was added individually, the pH alteration mildly to 6.72 and 7.60 severally. These values reflected per centum mistakes of 4.68 % and 3.06 % severally. The procedure was repeated with distilled H2O and the pH dropped to 1.64 and increased to 12.04 from 5.83. Phosphate buffer is thereby capable of defying drastic alterations in pH and therefore is utile as buffering agent that maintains favorable physiologic conditions in the cells.


Buffer solutions are indispensable in biochemical reactions because it decreases or defy the alteration of pH in a solution when acid or base is added. ( 1 ) Without the buffer, drastic alteration of pH will happen. An acidic buffer solution will hold a pH of less than 7, it is normally composed of weak acid. On the other manus, an alkalic solution will hold a pH of greater than 7 which have weak base. ( 2,3 )

Phosphate buffer is one illustration of buffer solutions, it is besides the most normally used buffer in common biochemical experiments. This buffer can be produced utilizing H3PO4 -H2PO4- or H2PO4 -H2PO4-2 ; the H3PO4 -H2PO4- system is normally being used to obtain acidic pH and on the other manus, H2PO4 -H2PO4-2 system is used to obtain a value near or above the pH.


Reagents are calculated for 250ml of 0.200M H2PO4 -H2PO4-2 buffer with pH 7.40. After ciphering, 5.13g of K2HPO4 and 2.65g of KH2PO4 were weighed. The weighed reagents were transferred quantitatively into a flask and H2O was added. The solution was filled-to-mark by H2O and wholly dissolved by inverting the flask at least 20 times. From the created buffer, a 25.0ml buffer was transferred into two separate flasks. The pH was measured and per centum mistake of the buffer was computed. In the first flask or solution, 10.0ml of 0.100 M HCl was added, it was swirled and the pH was measured. For the 2nd flask or solution, 10.0ml of 0.100M NaOH was added and it was besides swirled and the pH was besides measured. The on the job solutions are repeated but distilled H2O is used alternatively of the phosphate buffer. The fresh buffer was kept and stored and the used samples were disposed.

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The initial pH of the phosphate buffer theoretically is 7.40 but the existent measuring is 7.00 which had 5.41 of its per centum mistake. Upon adding the HCl solution, from its theoretical value of 7.05, it decreases to 6.74 which had 4.68 % of mistake. After adding NaOH solution in the buffer, the theoretical value of 7.84 lessenings with its existent value of 7.60 holding 3.06 % of mistake. For the distilled H2O, same procedure was done. A sample of 25ml H2O was measured holding 5.83 for its initial, 1.64 after adding HCl solution, and 12.04 after adding NaOH solution. ( See table 1 )

If the acid is added in a solution, the inclination of the pH is to hold lesser value from its original pH and if basal solution is added, the alteration of pH will be greater than the initial value. As to compare the information of the alteration of pH after adding acid and base in phosphate buffer and in distilled H2O, they are really different from one another. It was shown in the consequences ( see table1 ) that when phosphate buffer is used, the alteration in pH was really low or it does n’t increased or decreased excessively much. But as to compare with the distilled H2O, the consequences in pH had a drastic alteration. Meaning, if buffer is non used in a certain solution, the inclination is to hold a really high or really low alteration in pH because the presence of buffer resists the drastic alteration in pH.

Table 1: Summary of pH Valuess of Phosphate Buffer Against Distilled Water


Phosphate Buffer

Distilled Water



% Mistake




5.41 %


+10.0ml of 0.100 M HCl



4.68 %


+10.0ml of 0.100 M NaOH



3.06 %


As the experiment was conducted, it was seen that buffers are indispensable during biochemical reactions. There are besides some man-made buffers that were used for different reactions, one of these was HEPES or N-2-Hydroxyethylpiperazine-N’-2-ethanesulfonic acid, is a general buffer which has zwitterionic type. The Hepes buffer does non adhere with Mg, Ca, manganese and copper ions. It avoids adhering from non receptor stuffs. Another illustration of buffer is PIPES or piperazine-N, N’-bis ( ethanesulfonic acid ) ; 1,4-piperazinediethanesulfonic acid, this buffer is developed to run into the standards for midrange pKa, maximal H2O solubility and minimal solubility in all other dissolvers, minimum salt effects, minimum alteration in pKa with temperature, chemically and enzymatically stable, minimum soaking up in seeable or UV spectral scope and easy synthesized. ( 5 )

Figure 2: Structure of PIPES

Figure 1: Structure of HEPES

The phosphate buffer plays a major function in buffering the nephritic tubular fluid and intracellular fluids. Another important buffer is the carbonaceous acid-bicarbonate buffer, it maintains the blood plasma and ECF pH at normal rate. The hydrogen carbonate nowadays than carbonaceous acid, the normal metamorphosis produces more acids than bases which is consistent with the organic structure ‘s demands. The blood with higher base concentration is able to neutralize the acid produced from metamorphosis. Since reasonably little sums of bases are produces, the carbonaceous acid concentration in the blood can be lower. ( 6 )

Abnormalities occur when inordinate acid or base flows out through the system. One is Acidosis, this occurs when blood pH falls below 7.35 due to acid production within the organic structure, ingestion of substances that metabolizes to acids, decreased acerb elimination and increased elimination of base. Acidemia is one illustration of abnormalcies in blood. Another job is Alkalosis, is the state of affairs wherein there is an inordinate base in the blood that causes the pH to lift above 7.45 due to electrolyte perturbations caused by drawn-out emesis or terrible desiccation, ingestion of base and hyperventilation. ( 7 )


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