Chapter 14- Enzyme Inhibition Flashcards
(41 cards)
Inhibitors are substances that interfere with ______ by _______ enzymatic reactions
catalysis
slowing or halting
Two classes of inhibitors:
- Reversible
- Irreversible
Reversible inhibitors use _____ bonds that form ____ but break _____
weak
rapidly
easily
Which type of inhibitor does not permanently disable the enzyme?
reversible inhibitors
Reversible inhibitors come to an equilibrium with the enzyme to form ____
enzyme inhibitor complex (EI)
Irreversible inhibitors are known as:
enzyme inactivators
Irreversible inhibitors combine with enzymes through _____
strong (usually) covalent bond
An enzyme is ___ when paired with an irreversible inhibitor
permanently disabled
irreversible inhibitors are ______ dependent
time
for irreversible inhibitors, you cannot apply____
Michaelis-Menton kinetics
Depending on their nature, reversible inhibitors will effect____ or _____
Km
Vmax
Km and Vmax are measured in _______ which gives the ____
presence of inhibitor
apparent Km or Vmax
Competitive inhibitors _____ with substrate binding
compete
The substrate and competitive inhibitor are typically ____
mutually exclusive
Competitive inhibitors typically binds ____- to the enzyme
reversibly
The winner of the competition between competitive inhibitors and substrates depends on the ______
the concentration of each.
Competitive inhibitors bind to _____ but not to _____
free enzyme
ES complex
Competitive inhibitors will _____ Km, because ____
increase
because there is no affinity for S when EI has been made which reduces affinity and increases Km
Competitive inhibitors will ___ Vmax, because ____
not change
Vmax is the velocity of very high [S] which means inhibitor will not inhibit the enzyme bc it is out competed and doesn’t slow down the rxn
Uncompetitive inhibitor is ____ of binding to free E
incapable
Uncompetitive inhibitors only bind to the _____
ES complex
How do uncompetitive inhibitors inactivate the enzyme?
causes structural distortion of the active site
Effect of low [S] on uncompetitive inhibitors
inhibitor cannot bind bc most enzyme are free, making the inhibitor ineffective
Effect of high [S] on uncompetitive inhibitors
Inhibitor can bind bc most E is in ES complex, making the inhibitor effective.
