to describe the Lock and Key Hypothesis of enzyme action

They are basically 6
followed by 6 so that’s 6,000,000 per minute, which is a staggering number.
If you join me on the next video, we will be looking at the rates of reaction and how
enzymes can be affected by different conditions.
[end of audio 4:15] A Level Biology: Enzymes 2 – Induced Fit
and Lock & Key Theory Page…2

BBC - GCSE Bitesize: The lock and key mechanism

This lock and key hypothesis does not give the whole picture, though; enzymes are more subtle.

Enzymes Lock & Key Hypothesis - [PDF Document]

Not all experimental evidence can be adequately explained by using the so-called rigid enzyme model assumed by the lock and key theory. For this reason, a modification called the induced-fit theory has been proposed.

small problem with the 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).


lock and key hypothesis and inhibition discussed | …

Enzymes are specific. Only molecules with the correct shape can fit into the enzyme. Just like only one key can open a lock, only one type of enzyme can speed up a specific reaction. This is called the lock and key model.

Title: LOCK AND KEY 1 Hird Hermon Industries Proudly Present..

Enzymes are also specific in their reactions to substrates. Usually only certain enzymes will catalyse certain reactions. The degree of specificity varies from enzyme to enzyme, for example digestive enzymes will work on a wide variety of reactions and substrates. Specific reactions can be illustrated by a ‘lock-and-key’ diagram which illustrates the fact the only on type of substrate will fit the enzyme, like putting a key into a lock, as shown below:

What is the difference between the lock-and-key model …