Enzymes-The specificity and inhibition of lactase
Which of the disaccharides tested is/are recognized and hydrolyzed by lactase?
Answer
Lactose disaccharide. Lactase breaks only lactose disaccharide and not any other into galactose and glucose due to the shape of the sugar. Also, lactase catalyzes disaccharide lactose hydrolysis to its simple sugars’ galactose and glucose.
Which of the compounds tested INHIBIT (reduce) the activity of lactase?
Answer:
Galactose and maltose compounds. Lactase can be inhibited by three main dietary sugars, such as fructose, galactose, and glucose, and not only seen in hydrolysis products. The reason behind the reducing activity of lactase by the compound is because they are reducing disaccharides.
Explain how the inhibiting compound(s) might lower the activity of lactase.
Answer:
In the case of galactose, it is a competitive inhibitor that competes with the ONPG based on the active site of the enzyme. It inhibits the reacting by preventing the ONPG and make contact with the active site. Maltose is a reducing disaccharide that inhibits the breaking down of lactose by lactase. Thus, the compounds prevent the severing of beta-glycosidic linkage in lactose.