Enzymes - Inhibition

Question 1

what is an enzyme inhibitor

Answer 1

any substance or molecule that slows down the rate of an enzyme-controlled reaction by affecting the enzyme molecule in some way

Question 2

what are reversible inhibitors

Answer 2

do not permanently bind to the enzyme, can be removed

Question 3

what are irreversible inhibitors

Answer 3

permanently bind to the enzyme and cannot easily be removed

Question 4

what affects whether or not an inhibitor is reversible or irreversible

Answer 4

the strength of the bonds between an enzyme and inhibitor

Question 5

what will the bonds be for reversible inhibitors

Answer 5

ionic or hydrogen

Question 6

what will the bonds be for irreversible inhibitors

Answer 6

covalent

Question 7

what are competitive inhibitors

Answer 7

molecules with a similar shape to the substrate molecules. They compete with substrate molecules to bind to the active site (complementary), blocking it so that no reaction takes place.

Question 8

what does the level of inhibition depend on for competitive inhibitors

Answer 8

relative concentrations of inhibitor and substrate. If there is a higher concentration of inhibitor, there will be fewer active sites available for the substrate.

Question 9

what are non-competitive inhibitors and how do they work

Answer 9

molecules that bind to the enzyme away from its active site (in allosteric site) and cause a change in tertiary structure of the protein, causing the active site to change shape so substrate can no longer bind to it.

Question 10

what happens to reaction rates as a result of non-competitive inhibitors

Answer 10

decrease

Question 11

what effect will increasing substrate concentration have on non-competitive inhibitors

Answer 11

won’t make a difference to reaction rates as the enzyme activity will still be inhibited