The chemistry club is hosting its annual information meeting this Friday (October 6th) at 2 pm in the chem. library.

1. The chemistry club is hosting its annual information meeting this Friday (October 6th) at 2 pm in the chem. library. Come meet the council,learn about upcoming events and have some pizza. There are leadership opportunities available, and many ways to get involved. Everyone is welcome. Following this event, the Chem department will host its annual graduate school information seminar. CB285.

2. Acids, Bases and Buffers!!!Here’s a site for remedial work

3. [H+] [OH-] [H2O] = 55 M!!! Keq= [H2O] KW= [H+] [OH-] = 10-14 pH = -log [H+] pOH = -log [OH-] -log KW = -log{= [H+] [OH-]} pKW= pH + pOH = 14

4. Strong vs. weak acids Conjugate acid/base pairs. Examples: Calculate the pH for a solution of 0.2 M HCl. (How would you prepare this HCl?)

5. Figure 2-10 Acid-base titration curves of 1-L solutions of 1M acetic acid, H2PO4–, and NH4+ by a strong base. Page 46

6. ANIMATIONS Look at these on your own: Fig. 2-15 and 2-16

7. HA  H+ + A- Ka = [H+][A-] [HA] -log Ka = - log{[H+][A-]/[HA]} pKa= -log [H+] - log [A-]/[HA] pH = pKa + log [A-]/[HA]

8. Acids, Bases and Buffers!!! The Henderson-Hasselbach Equation: pH = pKa + log [A-]/[HA]

9. Examples: Calculate the pH for a solution of 0.2 M HCl. Add 10 mL of this solution to 50 mL of 0.2 M NaAc (pK=4.7). Now what is the pH? In what pH range is acetate a “good” buffer? How could you prepare 2 L of a solution of sodium acetate pH=5.

10. Amino Acids: Chapter 4

12. Figure 4-1 General structural formula for a-amino acids. Page 65 What’s wrong with this structure?

13. Figure 4-11 Schematic diagram of a polarimeter. Page 72

14. Figure 4-12 Fischer convention configurations for naming the enantiomers of glyceraldehyde. Page 73

15. Figure 4-13 Configuration of L-glyceraldehyde andL-a-amino acids. Page 73

16. Figure 4-14 “CORN crib” mnemonic for the hand ofL-amino acids. Page 73

17. Figure 4-2 Zwitterionic form of the a-amino acids that occur at physiological pH values. Page 65

18. NONchiral Stryer Fig.3.7

19. Figure 4-18 The structural formula of L-alanine. Page 75

20. Stryer Fig.3.8

21. Figure 4-19 Newman projection diagrams of the stereoisomers of threonine and isoleucine derived from proteins. Page 75

22. Stryer Fig.3.9

23. Stryer Fig.3.10

24. Figure 4-4a Structure of phenylalanine. (a) Ball and stick form. Page 69

25. Figure 4-4b Structure of phenylalanine. (b) Space-filling model. Page 69

26. Stryer Fig. 3.11: Phe absorbs a little as well. This phenomenon is the basis of one method to determine protein concentration in a non-destructive manner using Beer’s Law. Beer Beer Beer

27. Stryer Fig.3.13

28. Stryer Fig. 3.20

29.     Stryer Fig.3.14

30. Figure 4-9 Greek lettering scheme used to identify the atoms in the glutamyl and lysyl R groups. Page 71

31. Figure 4-5 Structure of cystine. Page 69

32.    Stryer Fig.3.16

33. Amino acid structures http://info.bio.cmu.edu/Courses/ BiochemMols/AAViewer/ AAVFrameset.htm

34. Figure 4-22 Some uncommon amino acid residues that are components of certain proteins. Page 77

35. Figure 4-23 Some biologically produced derivatives of “standard” amino acids and amino acids that are not components of proteins. Page 77

36. Ionic properties of amino acids impart ionic properties to proteins • in general these are SURFACE properties (i.e. charged sidechains are on solvent-exposed outside of folded structure) • affect protein-ligand binding (e.g. DNA-binding proteins) or catalysis • average charge on protein is an important consideration in the design of a purification process

38. Table 4-1 (left) Covalent Structures and Abbreviations of the “Standard” Amino Acids of Proteins, Their Occurrence, and the pK Values of Their Ionizable Groups. Page 66

39. Table 4-1 (right)Covalent Structures and Abbreviations of the “Standard” Amino Acids of Proteins, Their Occurrence, and the pK Values of Their Ionizable Groups. Page 67

40. Figure 4-6 Titration curve of glycine. Page 70