Enzymes at Work - Inhibitors of aciton

Question 1

What is an inhibitor?

Answer 1

• An inhibitor is any substance/molecule which slows down the rate of reaction.

Question 2

What may inhibitors effect?

Answer 2

• Some inhibitors affect just one active site of just one enzyme. Some affect multiple enzymes and places other than the active site.

Question 3

What are competitive inhibitors and how do they work?

Answer 3

• Competitive inhibitor molecules have a similar shape to that of the substrate molecule. They can occupy the active site, effectively forming an enzyme-inhibitor complex.

Question 4

What are non-competitive inhibitors and how do they work?

Answer 4

• Non-competitive inhibitors do not compete with substrate molecules for a place in the active site. This is reversible, vital for metabolic functions, regulating enzyme activity. They attach elsewhere and distort the tertiary structure of the enzyme molecule. Changes shape of active site so cannot bind. Changing substrate concentration has no effect on form of inhibition.

Question 5

Do competitive enzymes bind permanently?

Answer 5

• Most competitive inhibitors do not bind permanently – leaves enzyme molecules unaffected.

Question 6

Do non-competitive inhibitors bind permanently?

Answer 6

• Many non-competitive inhibitors bind permanently to enzyme molecules, it is irreversible, and enzyme molecules are effectively denatured.