1. How does competitive inhibitor affect Km and Vmax?
3. Explain why for each.
- 1. Vmax stays constant while Km increases (less affinity)
- 2. Vmax decreases while Km stays constant.
For competitive inhibitor (CI), assuming same binding affinity for substrate, Km increases b/c it will require more S to reach Km point (1/2 of Vmax) Vmax stays constant b/c competitive inhibition can be overcome by sufficiently high [S]
For noncompetitive inhibitor - Vmax decreases as a result of removing activated complex, but since I doesn't interfere with binding site, Km stays the same. It doesn't matter how much substrate is added, Vmax will decrease.