Enzyme inhibitors

Question 1

Why is controlling the activities of enzymes important?

Answer 1

regulates the rat eand quantity of product fromation

Question 2

What are inhibitors?

Answer 2

molecules that prevent enzymes from carrying out their normal function of catalysis (or slow them down)

Question 3

What are the two types of inhibtor?

Answer 3

competitive and non-competitive

Question 4

How do competetive inhibitors work?

Answer 4

1. A molecule or part of a molecule that has a similar shape to the substate of an enzymes can fit into the active site of an enzyme
2. this blocks the substrate from entering the active site, preventing the enzyme from catalysing the reaction
   
   1. the enzyme cannot carry out its normal function and is said to be inhibited

Question 5

Why are competitive inhibitors competitive?

Answer 5

substrate and inhibitor molecules present in a solution will compete with each other to bind to the active sites of an enzymes catalysing the reaction

this will reduce the number of substrate molecules binding to active sites in a given time and slows down the rate of reaction

Question 6

What does the degree of inhibition depend on with competitive inhibitors?

Answer 6

the relative concentrations of substrate, inhibitor an enzyme

most competitive inhibtors only bind temporarily to the active site of the enzyme, so their effect is reversible

Question 7

What is the effect on the rate of reaction when a competitive inhibitor is added?

Answer 7

reduces the rate of reaction for a given concentration of substrate, but it does not change the Vmax of the enzyme it inhibits

Question 8

Why can Vmax still be reached?

Answer 8

the substrate concentration has to be increased enough so that there will be so much more substrate than inhibitor that the original Vmax can still be reached

Question 9

What are statins?

Answer 9

competitive inhibitors of an enzyme used in the synthesis of cholseterol

statins are regularly prescribed to help people reduce blood cholesterol concentration

high blood cholesterol levels can result in heart disease

Question 10

What is asprin?

Answer 10

asprin irreversibly inhibits the active site of COX enzymes, preventing the synthesis of prostaglanding and thromboxane, the chemicals responsible for producing pain and fever