Question

As lactose approaches the active site of lactase, as shown in the image, which of the following occurs first?

The lactose molecule is broken into glucose and galactose.
Lactase shifts to its lowest free energy level to allow lactose to enter the active site.
Lactose creates a microenvironment as it approaches lactase to promote binding.
Temporary bonding occurs between the active site and the substrate, causing a conformational change.

Answer 1

There is no image attachment, however, this question can be answered based on general understanding of enzymes. The answer is:

Temporary bonding occurs between the active site and the substrate, causing a conformational change.

Step-by-step explanation:

Enzymes are proteinous molecules that acts as catalyst in biochemical reactions by speeding up the rate of reactions. According to this question, lactase is an enzyme that acts on lactose sugar and breaks it down into its monomeric unit (glucose and galactose).

All enzymes possess an active site, with which they bind to their substrate. In this question, the lactose (substrate) approaches the active site of lactase (enzyme), what occurs first is that a temporary bonding occurs between the active site and the substrate, causing a conformational change in the shape of the enzyme.