What are weak bonds that allow flexibility in an enzyme

Enzymes are characterized to have weak bonds because their tertiary structure could easily bend and break because it will have to adjust to the shape of the substrate. It could be done via induced fitting or lock-and-key theory. These weak bonds are intermolecular forces like the London forces, electrostatic interactions and hydrogen bonding.

D.na is the answer hope this

Yes it would be a physical change.