Indicate which of the following criteria are important for the selection of a buffer to use in an in vitro biochemical reaction.
(Select all that apply.) a. The molecular weight of the chosen buffer should be in the range of 150 g/mol to 650 g/mol.
b. The chosen buffer should not interfere with the biochemical reaction.
c. The makeup of the chosen buffer should include only carbon, hydrogen, nitrogen, oxygen, and phosphorus.
d. The pKa of the chosen buffer should be close to the optimal pH for the biochemical reaction.
e. The chosen buffer should have a much higher concentration of its protonated species compared to the concentration of its deprotonated species at the optimal pH for the biochemical reaction.
The correct answer is: d. The pKa of the chosen buffer should be close to the optimal pH for the biochemical reaction.
Explanation:
The buffer resist or maintain the change in pH in case of Acid or basic addition to the solution. The buffer capacity should be within one or two pH units when compared to the optimal pH.
Thus it is important to select a buffer with pKa close to the optimum pH of the reaction because the ability for the buffer to maintain the pH is is great at the pH close to pKa.
