Why Does PH Affect Enzyme Activity?

According to Florida State Universtiy, pH affects enzyme activity by altering or inhibiting an enzyme from catalyzing a reaction. Changes in pH affect polar and non-polar forces, alter the shape of an enzyme and the active site, and cause the chemical change to occur ineffectively or not at all.

Florida State University states that basic groups in acidic solutions will be protonated while acidic groups in basic environments will be deprotonated. This alters the electrical attractions between polar groups.

Florida State University claims that every enzyme has an optimum pH range. Some enzymes, such as those in the stomach, function best at very low acidic pH levels. Other enzymes, such as those in saliva, function best near neutrality. Still other enzymes such as lipases function best at basic pH levels.

Florida State University explains the effects that pH levels have on enzyme activity by using two examples describing enzymes found in the blood. One example is acidosis, which occurs when pH levels drop in the blood, shifting the enzymes in the blood out of their optimum pH range. Another example is alkalosis which occurs when pH levels rise exponentially high causing enzymes to function ineffectively. Florida State University explains that these conditions do normally not occur because of the buffers found in the blood. These buffers are substances that resist change in pH and restrict the pH levels to a narrow range. The many buffers found in the body adjust pH levels so that enzymes can continue to catalyze their reactions.