Subject: Do you like to win? How about free stuff?

1. Subject: Do you like to win? How about free stuff? Well, you can do both if you submit the winning chemistry club T-shirt design. Designs may be submitted in the chemistry library in the box near the microwave - you can't miss the big black arrow showing you the way. Designs are due the Friday of finals week (December 15, 2006) at 4:30 PM. Check out the attachments for a look at last year's winning designs and a totally awesome poster. Your friendly FUNdraising chem. club coordinator, Tricia

2. Nov 20Liliya A. Yatsunyk Ph.D. Northwestern University, "Synthesis, Structure, and Magnetic Spectroscopies of Non-Planar Hemes as Models of the Cytochromes b Heme Centers" 4:00 SL 130 Nov 21Melinda Kangala, Graduate Student, Western Washington University (Chemistry). Thesis Defense. 3:00 p.m. BI 212 Nov 28Danielle Dube Ph.D. Stanford University "Chemical Tools to Target and Understand Glycosylation" 4:00 p.m. SL 130

4. Wednesday 29th November, Dr. Vett Lloyd will be presenting her seminar: "Dolly the fly - why the world needs cloned Drosophila." Dr. Lloyd is an associate professor from Mount Allison University, New Brunswick Canada. She studies chromatin structure and gene regulation using the fruit fly Drosophila as a model. She is particularly interested in parent of origin effects such as imprinting, and the particular epigenetic (ie., chromatin-based) problems encountered during the process of cloning complex eukaryotes. She also has a pretty awesome website (Drosophiloid.ca) which provides summaries of her research, in addition to expert tips for getting rid of flies in your home.

5. Ch 14 Kinetics!

6. New Kinetic Parameter: Kcat= Vmax [ET] when Kcat+ <<[S] “Turnover Number”

7. Previously defined Vo =k2[ES] and [ES] = [E][S] KM Vo= kcat[E][S]/KM When [S]<<KM. [E][ET] Vo= kcat[E]T[S]/KM Kcat/KM = rate constant for interaction of E and S (turnover number) Can be used to measure an enzyme’s preference for different substrates.

8. What do these values tell you?

9. Determining kcat and KM from “intial rate” data o

10. Vmax = 150-160?? Km = ???

11. Vmax = 150-160?? Km = ??? Lineweaver- Burk plot Vmax = 164 mM/min Km = 32.2 mM

12. Figure 14-9 A double reciprocal (Lineweaver–Burk) plot. Page 480

14. Table 14-1 Values of KM, kcat, and kcat/KMfor Some Enzymes and Substrates. Page 480

16. How does the substrate contact the enzyme?

17. Figure 14-10 Cross section through the active site of human superoxide dismutase (SOD). Cu+2 and R 143 form the binding site for O2-. Page 481

18. Inhibiting Enzyme Activity Reversible Irreversible Competetive Uncompetetive Mixed

19. Stryer Fig. 8.15: Types of inhibition

20. Stryer Fig. 8.16: Methotrexate inhibits the formation of THF from DHF by binding very tightly to the enzyme Dihydrofolate reductase. DHFR is required for regenerating THF, which is required for TMP synthesis.

21. Another important competitive inhibitor helped Sir Hans Krebs elucidate the TCA cycle: Malonate Succinate DH CO2--CH2-CH2-CO2- + FAD  CO2--CH=CH-CO2- + FADH2 Succinate What type of rxn is this? What’s missing? Name S and then name E. Inhibitor is malonate: CO2--CH2-CO2- WHY?

22. Figure 14-11 Competitive inhibition. Page 484

23. Stryer Fig. 8.17: Competitive Inhibition

24. Figure 14-12 Lineweaver–Burk plot of the competitively inhibited Michaelis–Menten enzyme described by Fig. 14-11. Page 484

25. competitive inhibition KM increases; Vmax unchanged + inhibitor 1/Vo Vmax no inhibitor 100 Vo 75 50 + inhibitor no inhibitor 25 0 [S] 1/[S] 0 10 20 30 KM -1/KM

26. Stryer Fig. 8.18: Non-competitive Inhibition EDTA

27. Uncompetetive: I interacts with ES Mixed: I interacts with either E or ES (or both)

28. Table 14-2 Effects of Inhibitors on the Parameters of the Michaelis–Menten Equationa Page 486

29. Inhibitor binds at Effect on Vmax Effect on KM other competitive Active site None Apparent KM increases Overcome inhibition at high [S] uncompetitive Allosteric site after S binds decreases Apparent KM decreases noncompetitive (mixed) Allosteric site (to E or ES) decreases varies Summary of simple inhibition models

30. Figure 14-14 Lineweaver–Burk plot of a simple Michaelis-Menten enzyme in the presence of a mixed inhibitor. Page 486

31. Irreversible Inhibition V vs. S looks like noncompetitive inhibition.

34. Stryer Fig. 8.20

35. Stryer Fig. 8.19

36. Stryer Fig. 8.21

37. Proline racemase (bacterial) Stryer 8.24 Transition state analogs are potent inhibitors.

38. Suicide Inhibitor Stryer Fig. 8.23 Inhibition of monoamine oxidase, an enzyme involved in inactivating neurotransmitters such as dopamine.

39. Two substrate reactions

40. What would you name this enzyme? (In this case it is named for the reverse rxn). So 1. name the product. 2. What category of enzyme is this? LDH Absorbs light at 340 nm Ordered Sequential Displacement: All substrates bind E before any P is produced in a specific order. Stryer p. 207

41. An ordered “Bi-Bi” reaction

42. Random Sequential Displacement: order not specified.

43. Figure 14-17 Some bisubstrate reactions. (a) The peptide hydrolysis reaction catalyzed by trypsin. (b) The alcohol dehydrogenase reaction. Page 488

44. Figure 14-13 Lineweaver–Burk plot of a simple Michaelis–Menten enzyme in the presence of uncompetitive inhibitor. Page 485