In an experiment, the enzyme lactase is added to milk in a test tube. The products obtained are glucose and galactose. Which of these correctly explains the function of the enzyme in this reaction?

a. The enzyme molecules collide with the substrate and break it into simpler products.

b. The enzyme has active sites where the substrate binds with the enzyme to form a complex.

c. The substrate binds at the non-active sites of the enzyme, where it is broken down into simpler compounds.

d. The substrate breaks the bonds of the enzyme, resulting in the formation of simpler products.

Answer;

The enzyme has active sites where the substrate binds with the enzyme to form a complex.

Explanation;

-Enzymes catalyze chemical reactions involving the substrate (s). In the case of a single substrate, the substrate bonds with the enzyme active site, and an enzyme-substrate complex is formed. The active site consists of residues that form temporary bonds with the substrate (binding site) and residues that catalyse a reaction of that substrate (catalytic site).

-After binding of the enzyme to the substrate is initiated, a conformation change in the shape of the active site which results in a new shape of the active site that is complementary to the shape of the substrate. At the catalytic site the substrate is converted to products.