Enzyme kinetics Flashcards
What is chymotrypsin?
Serine protease found in the digestive system.
What does chymotrypsin target?
Hydrophobic side chains.
What is Km used for?
The Km value is useful as a means of comparing the strength of Enzyme-Substrate complexes.
What does a low Km indicate?
Tight binding of a substrate to an enzyme.
What does a high Km indicate?
Weak binding of a substrate to an enzyme.
In a Lineweaver-Burk plot what does the gradient of the curve represent?
Km / Vmax
In a Lineweaver-Burk plot what does the y intercept represent?
1/Vmax
In a Lineweaver-Burk plot what does the x intercept represent?
-1/Km
How do competitive enzyme inhibitors work?
Occupies all or part of the active site of an enzyme.
Competitive enzyme inhibitor effects on Km and Vmax?
Inhibits KM but have no effect on Vmax. Simply adding enough substrate will outcompete the antagonist.
How do non competitive enzyme inhibitors work?
Bind outside of the enzyme active site and induce conformational changes in such that enzyme function is inhibited.
Non competitive inhibitor effects on Km and Vmax?
Non-competitive inhibitors have no effect on KM but act to lower Vmax.
How is turnover number (kcat) calculated?
Vmax / concentration of enzyme.
What does the turnover number (kcat) mean?
Number of molecules that an enzyme can process in a given unit of time.
