The chemistry club is hosting its annual information

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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.
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Acids, Bases and Buffers!!!Heres a site for
remedial work
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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
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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?)
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Figure 2-10 Acid-base titration curves of 1-L
solutions of 1M acetic acid, H2PO4, and NH4 by
a strong base.
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ANIMATIONS
Look at these on your own Fig. 2-15 and 2-16
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HA ? H A-
Ka HA-
HA
-log Ka - logHA-/HA
pKa -log H - log A-/HA pH pKa log
A-/HA
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Acids, Bases and Buffers!!!
The Henderson-Hasselbach Equation pH pKa
log A-/HA
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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
(pK4.7). 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 pH5.
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Amino Acids Chapter 4
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Figure 4-1 General structural formula for a-amino
acids.
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Whats wrong with this structure?
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Figure 4-11 Schematic diagram of a polarimeter.
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Figure 4-12 Fischer convention configurations for
naming the enantiomers of glyceraldehyde.
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Figure 4-13 Configuration of L-glyceraldehyde
andL-a-amino acids.
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Figure 4-14 CORN crib mnemonic for the hand
ofL-amino acids.
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Figure 4-2 Zwitterionic form of the a-amino acids
that occur at physiological pH values.
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NONchiral
Stryer Fig.3.7
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Figure 4-18 The structural formula of L-alanine.
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Stryer Fig.3.8
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Figure 4-19 Newman projection diagrams of the
stereoisomers of threonine and isoleucine derived
from proteins.
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Stryer Fig.3.9
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Stryer Fig.3.10
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Figure 4-4a Structure of phenylalanine. (a) Ball
and stick form.
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Figure 4-4b Structure of phenylalanine. (b)
Space-filling model.
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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 Beers Law.
Beer
Beer
Beer
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Stryer Fig.3.13
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Stryer Fig. 3.20
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?
?
?
?
Stryer Fig.3.14
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Figure 4-9 Greek lettering scheme used to
identify the atoms in the glutamyl and lysyl R
groups.
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Figure 4-5 Structure of cystine.
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Stryer Fig.3.16
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Amino acid structures
http//info.bio.cmu.edu/Courses/ BiochemMols/AAVie
wer/ AAVFrameset.htm
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Figure 4-22 Some uncommon amino acid residues
that are components of certain proteins.
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Figure 4-23 Some biologically produced
derivatives of standard amino acids and amino
acids that are not components of proteins.
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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

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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.
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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.
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Figure 4-6 Titration curve of glycine.
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