Enzyme inhibitors Flashcards
What are enzyme inhibitors?
Molecules that slow down or prevent enzyme reactions
What are the types of enzyme inhibitors?
Irreversibe
Reversible
- competitive
- non competitive
What do irreversible enzyme inhibitors do?
Form tight covalent bonds to enzyme
What do reversible enzyme inhibitors do?
Form weak non-covalent bonds to enzyme
can dissociate
How does the competitive inhibitor relate to the substrate?
Have somewhat similar shape
Where does a competitive inhibitor bind to an enzyme?
At its active site
How does a competitive inhibitor affect enzyme-substrate interactions?
Fewer enzyme active sites available
fewer substrates can bind
How does a competitive inhibitor affect Km? Why?
Higher Km
need more substrate concentration to reach Vmax/2
to outcompete competitive inhibitor
How does a competitive inhibitor affect Vmax? Why?
Vmax stays the same
if increase substrate concentration will eventually be able to reach Vmax
How is the rectangular hyperbola affected by a competitive inhibitor?
Is flatter but eventually reaches same end point
How is the lineweaver-burk plot affected by a competitive inhibitor?
Is steeper
Where does a non-competitive inhibitor bind to an enzyme?
Away from the active site
elsewhere on the enzyme
How does a non-competitive inhibitor affect the enzyme?
Causes conformational change in enzyme
and in its active site
How does a non-competitive inhibitor affect enzyme-substrate interactions?
Substrate cannot bind to enzyme active site
How does a non-competitive inhibitor affect Km?
Has no effect on Km
