MRCP UK EXAMINATIONS

Detailed explanation-1: -Salivary amylase has a relatively short active contact time with starch. Once a food bolus is swallowed and infiltrated with gastric juice, its catabolic activity is mostly stopped by low acidic pH.

Detailed explanation-2: -Typically the pH in the stomach is around 1.0 to 2.0, which is extremely acidic. This level of acidity causes salivary amylase’s protein structure to denature and change shape. Consequently, salivary amylase does not function once it enters the stomach.

Detailed explanation-3: -The optimum pH for the enzymatic activity of salivary amylase ranges from 6 to 7. Above and below this range, the reaction rate reduces as enzymes get denaturated. The enzyme salivary amylase is most active at pH 6.8.

Detailed explanation-4: -Abstract. Purified human pancreatic alpha-amylase (alpha-1, 4-glucan 4-glucano-hydrolase, EC 3.2. 1.1) was found to be stable over a wide range of pH values (5.0 to 10.5) with an optimal pH for the enzymatic activity of 7.0.