Question

According to the induced fit hypothesis of enzyme catalysis, _____.

(a) Remains unchanged when the substrate binds.
(b) Changes shape to fit the substrate more precisely.
(c) Is a rigid structure that the substrate must fit into.
(d) Is located on the inside of the enzyme molecule.

Answer 1

In the induced-fit model of enzyme action, both the enzyme and substrate molecules are flexible and adapt to each other's shape to facilitate the reaction. The active site of the enzyme changes shape to fit the substrate, allowing for optimal interaction and catalysis. The flexibility of the enzyme molecule ensures that it can return to its original form after the reaction.

Step-by-step explanation:

The induced-fit model of enzyme action accounts for the flexibility of enzyme and substrate molecules. According to this model, the flexibility of the enzyme molecule allows the active site to adapt to the shape of the substrate and, at the same time, the substrate adopts the shape of the enzyme to acquire the best possible orientation for the reaction to occur. The active site shape re-adjusts to let the products be released to allow the next cycle of the enzyme action. The observation from experiments during the actual catalysis reaction supports the view that not only does the active site of the enzyme change shape, the backbone and the side chains of the enzyme molecule remain in constant motion during the enzyme action.