3.3

Question 1

Describe how competitive inhibitors work. (3)

Answer 1

(1) They have a molecular shape SIMILAR to the substrate
(2) they TEMPORARILY OCCUPY the AS…
(3) which prevents substrates from binding to the AS

Question 2

As the concentration of substrate increases, the effectiveness of the competitive inhibitor… (1)

Answer 2

…decreases

Question 3

As the concentration of substrate increases, the effectiveness of the non-competitive inhibitor… (1)

Answer 3

…doesn’t change

Question 4

Describe how non-competitive inhibitors work. (3)

Answer 4

(1) they ATTACH themselves to the enzyme at a site other than the AS
(2) they alter the shape of the enzyme’s AS
(3) substrate molecules = can no longer bind to the enzyme at all.

Question 5

Describe the graph of the RoR when a competitive inhibitor is present. (2)

Answer 5

(1) increases as the amount of substrate increases,
(2) BUT less than without the competitive inhibitor

Question 6

Describe the graph of the RoR when a non-competitive inhibitor is present. (2)

Answer 6

(1) increases as the amount of substrate increases,
(2) then PLATEAUS in the middle of the graph.