Chemistry 30C

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Chemistry 30C

• Returning debts and review

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Debt 1

• Bonus question regarding leaving group

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Debt 2

• Why is imidazole more basic than pyridine?

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Debt 3

• Why is the pKa of the the a-amino group of Cys
  higher than usual?

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Debt 3

• The ammonium ion is stabilized by a neighboring
  group effect

Cys
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Last Debt

• What was that thing about protein modules and
  Star Wars?

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Tertiary Structure

• Proteins often comprise several modules that
  may vary in sequence but adopt the same
  3-dimensional structure
• Modules are like parts of machines with
  particular functions
• Module mostly are used for recognizing other
  proteins but also for maintaining the overall
  structure and for enzyme catalysis

SH2
SH3
PDZ
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Interested in research?

• Bitan Lab
• 1 SRP position available for spring quarter.
  More may open later.
• Send e-mail by next Friday
• Include resume, current transcripts, proposed
  duration, short explanation (no more than 1-2
  paragraphs) about your interest.
• Other labs
• http//www.mbi.ucla.edu/
• http//www.bri.ucla.edu/
• http//faculty.neuroscience.ucla.edu/institution/p
  ersonnel-list/
• http//www.neurology.ucla.edu/education/Fellowship
  s.Brochure.htm
• http//www.adc.ucla.edu/AA_faculty_staff.asp

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Final exam

• 10 questions
• 12 points each (maximum 120 points)
• Cumulative - chapters 19-24, 27
• Some emphasis on previously untested material
• 6 questions require translating names into
  structures

• Last office hours - Wednesday 3/21, 2-4 pm
• VOH for all other times

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Example question - peptide analysis

• Bradykinin is a 9-amino acid bioactive peptide
• AAA 2-Arg, 3-Pro, 1-Gly, 2-Phe, 1-Ser
• Trypsin Free Arg a peptide containing 1-Arg,
  3-Pro, 1-Gly, 2-Phe, 1-Ser
• 2 Edman cycles of the resulting peptide Pro, Pro
• Chymotrypsin Free Arg 2 peptides. First
  peptide - 1-Arg, 2-Pro, 1-Gly, 1-Phe. Second
  peptide - 1-Ser, 1-Pro, 1-Phe.
• 1 Edman cycle of second peptide Ser
• What is the sequence of bradykinin?

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Example question - Rubin 2000nomenclature

• Suggest a reasonable synthesis of
  1-chloro-3-propyl-5-nitrobenzene from benzene
• Suggest a reasonable synthesis of
  5-(N,N-dimethylamino)-2-(2-propoxy)benzoic acid
  from phenol

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Example question - pericyclic reactions and
orbitals

• What is the product of the reaction? (Maynard)
• Show the HOMO and LUMO orbitals involved

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Example question - pericyclic reactions (Maynard)
(Hint Cope)