Buffer solutions do not have an unlimited capacity to keep the pH relatively constant . Instead, the ability of a buffer solution to resist changes in pH relies on the presence of appreciable amounts of its conjugate weak acid-base pair. When enough strong acid or base is added to substantially lower the concentration of either member of the buffer pair, the buffering action within the solution is compromised.
The buffer capacity is the amount of acid or base that can be added to a given volume...

Buffer capacity is the quantitative measure of a buffer to resist the change in pH. As shown in the following equation, the buffer capacity, denoted by 'beta', is expressed as the number of moles of acid or base needed to change the pH of a one-liter buffer solution by 1 unit. Here, Ca and Cb indicate the number of moles of acid and base, respectively. Note that dpH represents the change in pH.
In the graph, pH is plotted as a function of the number of moles of base (Cb) added to a weak...

The carbonic acid-bicarbonate buffer system is critical for maintaining the body's pH balance. It operates on the equilibrium:

The human body utilizes protein buffer systems to maintain a stable pH. These systems capitalize on the dual role of amino acids, which can act as acids or bases by accepting or releasing hydrogen ions in response to pH changes. Protein buffer systems are particularly significant in the extracellular fluid (ECF) and intracellular fluid (ICF) of active cells, where structural and functional proteins provide substantial buffering capacity.
Certain amino acids can exist in a zwitterion state at a...

Acids are classified by the number of protons per molecule that they can give up in a reaction. Acids such as HCl, HNO3, and HCN that contain one ionizable hydrogen atom in each molecule are called monoprotic acids. Their reactions with water are: