The lock-and-key mechanism refers to

The Correct Answer is:

Emil Fischer was the first to describe the Lock-and-Key mechanism, which involves an enzyme momentarily binding to one substrate to generate a substrate complex.

The locking mechanism and key are frequently connected with complementary enzyme forms that share a single substrate, with the enzyme serving as the lock and the substrate as the key. One substrate (key) fits neatly into the enzyme’s active site (keyhole) (lock).

Physically, the substrate and the active site indicated before are compatible. This is where the enzyme’s temporary binding site is found. Like a lock and a key, the enzyme is designed to fit the lock and the substrate together.