Enzyme Inhibitors

Question 1

what are enzyme inhibitors?

Answer 1

molecules that prevent enzymes from carrying out their normal function.

Question 2

how do competitive inhibitors work?

Answer 2

1. molecule or part of a molecule with a similar shape to the substrate can fit into the active site of the enzyme.
2. this blocks the substrate from the active site so the enzyme cannot catalyse a reaction.
3. rate of reaction slows down as inhibitor competes with substrates for active sites to bind to.

Question 3

is competitive inhibation permanent?

Answer 3

mostly not. however, aspirin is.

Question 4

what is an example of competitive inhibition?

Answer 4

statins are competitive inhibitors of an enzyme used in synthesis of cholestrol. therefore, statins may be prescriped to reduce blood cholestrol concentration.

Question 5

how does non-competitive inhibition work?

Answer 5

1. the inhibitor binds to the enzyme at an allosteric site.
2. the binding of the inhibitor causes the teritary structure of theenzyme to change, active site changes shape.
3. active site no longer has a complementary shapeto the substrate.
4. enzyme cannot form enzyme-substrate complexes and is said to be inhibited.

Question 6

what are organophosphates?

Answer 6

they are used as herbicides and they irreversibly inhibit the enzyme acetyl cholinesterase, an enzyme necessary for nerve impulse transmission. This can cause muscle cramps, paralysis or death if accidentally ingested.

Question 7

what is end-product inhibition?

Answer 7

the term used for enzyme inhibition that occurs when the product of a reaction acts as an inhibitor to the enzyme that produces it.

Question 8

what enzyme catalyses the breakdown of glucose?

Answer 8

phosphofructokinase. competitively inhibited by ATP. the breakdown of glucose produces ATP so ATP catalyses its own production.