enzyme inhibitors

Question 1

what are enzyme inhibitors?

Answer 1

a number of chemicals can act as enzyme inhibitors, slowing down the rate of enzyme catalysed reactions

Question 2

what are the two types of inhibitors?

Answer 2

competitive inhibitors and non competitive inhibitors

Question 3

how do competitive inhibitors act? (3)

Answer 3

• the inhibitor has a similar structure to the normal substrate molecule and competes with it for attachment to the active site
• the rate of reaction is reduced as there are fewer enzyme-substrate complexes
• however, this inhibition can be reduced by the addition of more substrate

Question 4

draw a diagram of competitive inhibition

Answer 4

see diagram

Question 5

draw a graph to show how a competitive inhibitor affects the rate of reaction

Answer 5

see graph

Question 6

how do non competitive inhibitors act? (5)

Answer 6

• the inhibitor is not similar in structure to the substrate
• it combines at a position other than the active site (allosteric site) to form an enzyme/inhibitor complex altering the tertiary structure and active site shape of the enzyme
• the substrate cannot attach or the substrate binds but no product is formed
• the degree of inhibition is completely dependent on the amount of inhibitor present
• the addition of more substrate will not reduce this inhibition

Question 7

draw a diagram of non competitive inhibition

Answer 7

see diagram

Question 8

draw a graph to show how a non competitive inhibitor affects the rate of reaction

Answer 8

see graph