3.3.13.3 Enzymes

Question 1

What are enzymes?

Answer 1

Protein - base catalysts
Each enzyme is optimised for just one reaction
Usually globular

Question 2

What is the structure of an enzyme?

Answer 2

Has a cleft or crevice called the active site where the reaction takes place

Question 3

How do enzymes speed up the rate of reaction?

Answer 3

The reacting molecule fits precisely in the active site and is held in exactly the right orientation to react
The reacting molecule must bond to the active site temporarily by intermolecular forces
Whilst bonded, these forces promote the movement of electrons within the substrate that lower the activation energy for the reaction

Question 4

What is stereospecificity in terms of enzymes?

Answer 4

The active site can be so specific that it only catalyses the reaction of one enantiomer and not the other
This makes the enzyme stereospecific

Question 5

How can enzymes be denatured?

Answer 5

By changes in temperature and pH

Question 6

How does enzyme inhibition work?

Answer 6

By creating a molecule with a similar shape to the substrate, the molecule will bind to the active site and and block the substrate from reaching the active site