1. Lecture 3

2. The transition state has highest energy

3. What happens if you lower  G ‡

4.  G ‡ determines reaction rate Lower activation energy = More molecules climb over Therefore, more S  P

5. What does an enzyme do? It “stabilizes” the TS “Stabilizes” =

6. Annotate this figure!

7. Photograph/Scan figure Upload JPG to Dropbox: Bio98 AE Curve

8. General enzyme reaction pathway General reaction pathway for enzyme E + S E.S E.TS -> E + P

9. Huh. How does an enzyme do that? How do you stabilize the TS?

10. How does an enzyme stabilize the TS? Lock & Key model Induced fit model

11. Lock & Key: Substrate

12. Induced fit

13. http://web.chem.ucsb.edu/~molvisual/ABLE/induced_fit/index.html

14. Enzymes have “active sites” Small cleft or crevice in enzyme molecule Very small part of enzyme! Has defined 3D architecture http://web.chem.ucsb.edu/~molvisual/ABLE/induced_fit/index.html