Final answer:
Changing the shape of the active site on the lactase enzyme would decrease the rate of lactose digestion.
Step-by-step explanation:
The lactase enzyme is responsible for digesting lactose, a sugar found in milk and dairy products. The active site of the enzyme is where lactose binds and is broken down. If the shape of the active site is changed, it would no longer be able to properly bind lactose, leading to a decrease in the rate of lactose digestion.
For example, imagine the active site is like a lock and lactose is the key. If the shape of the lock is altered, the key won't fit and therefore cannot unlock the lock. Similarly, if the shape of the active site on the lactase enzyme is changed, lactose molecules won't be able to bind and be broken down, resulting in a decreased rate of lactose digestion.