Question

(a) What will happen if starch amylase mixture is incubated at $0^{0}C$ for half an hour ?
(b) Describe the role of temperature, pH and substrate affecting enzymatic activity.
(c)What would happen when salivary amylase that acts specifically on starch enter the stomach and mixes with gastric juice ?

Answer 1

(a) If starch amylase mixture is incubated at 0${}^0$ C for half an hour, the enzyme activity will reduce. All the enzymes have an optimum temperature at which their activity is maximum. Temperature below its optimum temperature will decrease its activity. Amylase will breakdown starch into simpler form at 0${}^0$ C but at very slow speed.

(b) All the enzymes have optimum temperature and pH at which their activity is maximum. Temperature and pH below or above its optimum level will reduce the activity of an enzyme. Increasing the substrate concentration increases the enzyme activity up to certain point. After this, the substrate concentration will not affect the enzyme activity as all the active sites of enzymes are occupied by substrate and addition of more substrate will not affect it.

(c) In mouth, salivary amylase breaks down starch into maltase. Gastric juice is acidic in nature. Salivary amylase will not breakdown starch if it enters in the stomach as its activity stops in acidic medium.