Active Site - Binding Mechanism

Binding Mechanism

There are two proposed models of how enzymes work: the lock and key model and the induced fit model. The lock and key model assumes that the active site is a perfect fit for a specific substrate and that once the substrate binds to the enzyme no further modification is necessary; this is simplistic. The induced fit model is a development of the lock-and-key model and instead assumes that an active site is more flexible and that the presence of certain residues (amino acids) in the active site will encourage the enzyme to locate the correct substrate, after which conformational changes may occur as the substrate is bound.