Question

What are the 2 forms of the substrate binding domain on a chaperonin? How does it relate to the ATP binding domain?

A) Closed and Open, ATP Binding Induces Opening
B) Linear and Circular, ATP Binding Stabilizes Circular Form
C) Helical and Sheet, ATP Binding Converts Helical to Sheet
D) Spherical and Tubular, ATP Binding Causes Spherical Form

Answer 1

The two forms of the substrate binding domain on a chaperonin are A) the open and closed states, with ATP binding inducing these conformational changes. This dynamic process is explained by the induced fit model, which suggests both enzyme and substrate change shape to facilitate the enzymatic reaction.

Step-by-step explanation:

The two forms of the substrate binding domain on a chaperonin are A) the open and closed states.

This relates to the ATP binding domain in that the binding of ATP induces conformational changes in the chaperonin that enable it to open and accept a substrate protein.

Once the ATP is hydrolyzed, the chaperonin can close to encapsulate the substrate protein for proper folding.

This overall process aligns with the induced fit model, which suggests both the enzyme and substrate undergo conformational changes upon binding.

The induced fit model expands upon the earlier lock-and-key model by describing a more dynamic interaction between enzyme and substrate.

When the enzyme and substrate come together, their interaction causes a shift in the enzyme's structure, optimizing its ability to catalyze the reaction and facilitate the transition of the substrate to the product.