Describe and explain the lock and key model of enzyme action, and how denaturation affects this.

The lock and key model of enzyme action describes how enzymes are specific for their substrates. The enzyme is the lock and the substrate is the key. Much how every key is specific for a lock, every enzyme is specific for a substrate. When the substrate binds to an active site on the enzyme it begins to work. If the enzyme becomes denatured, through temperature or pH for example, the active site will change shape and no longer be functional. The enzyme will no longer be able to bind specifically to the active site and the function of the enzyme will be decreased or stopped.