Module 2.4 Enzymes

Question 1

DEFINE: Enzyme:

Answer 1

An enzyme is a biological catalyst in which speeds up chemical reactions by lowering activation energy. They are not used up in the reaction.

Question 2

How do enzymes wok?:

Answer 2

Enzymes allow reactions to proceed at lower than expected temperatures by lowering the activation energy required to bring about a reaction. The enzymes have a specific single function catalysing one reaction with one substrate. They are specific through the shape of their active site.

Question 3

What does enzyme action rely upon?:

Answer 3

Enzymes rely upon successful collisions between enzymes active site and substrate, in which these collisions are random.
They must also be between the correct enzyme and substrate - the shape has to complementary otherwise you cannot form an enzyme-substrate complex.

Question 4

Describe the Lock and Key model:

Answer 4

An enzyme fits exactly into the active site of an enzyme forming an enzyme-substrate complex, then the reaction will take place and an enzyme product complex is formed, before the products are finally released.

Question 5

Describe the induced fit model:

Answer 5

A substrate will not fit perfectly into the active site yet, the active site will go through a conformational change to allow the substrate to bind.