Explain the lock and key model of enzyme action?

Answer 1

Specific enzymes will only react with specific substrates, just like there are specific keys for specific locks.

Answer 2

Lock and Key Theory:

The specific action of an enzyme with a single substrate can be explained using a Lock and Key analogy first postulated in 1894 by Emil Fischer. In this analogy, the lock is the enzyme and the key is the substrate. Only the correctly sized key (substrate) fits into the key hole (active site) of the lock (enzyme).

Smaller keys, larger keys, or incorrectly positioned teeth on keys (incorrectly shaped or sized substrate molecules) do not fit into the lock (enzyme). Only the correctly shaped key opens a particular lock.

Answer 3

It states that an enzyme and its respective substrate can only interact if they fit perfectly (like a key fits a lock perfectly). This means that there are very particular relationships between certain enzymes and certain substrates. This differs from other theories that assume an enzyme can change shape in order to fit various substrates according to the conditions.

Answer 4

The active site on the enzyme molecule forms a "keyhole" into which the substrate(s) fit like a key. If the enzyme is denatured, it loses its basic shape, and the "key" will no longer fit- the enzyme loses its ability to function.