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CHMI 2227E Biochemistry I. Amino acids: Structure General chemical properties. Proteins: Building blocks of life!. C a. COOH. H. C. NH 2. R. Amino acids. General properties of amino acids. Net charge: 0. Net charge: -1. Net charge: +1. pKa 1 (pH 2-2.5). pKa 2 (pH 9-10.5).
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CHMI 2227EBiochemistry I Amino acids: Structure General chemical properties CHMI 2227 - E.R. Gauthier, Ph.D.
Proteins: Building blocks of life! CHMI 2227 - E.R. Gauthier, Ph.D.
Ca COOH H C NH2 R Amino acids CHMI 2227 - E.R. Gauthier, Ph.D.
General properties of amino acids. CHMI 2227 - E.R. Gauthier, Ph.D.
Net charge: 0 Net charge: -1 Net charge: +1 pKa 1 (pH 2-2.5) pKa 2 (pH 9-10.5) Basic pH Acidic pH Zwitterion General properties of amino acids. CHMI 2227 - E.R. Gauthier, Ph.D.
Buffer! Buffer! Amino acid titration1. simplest scenario CHMI 2227 - E.R. Gauthier, Ph.D.
The twenty amino acids: CHMI 2227 - E.R. Gauthier, Ph.D.
Structure of the 20 amino acids1. Hydrophobic amino acids CHMI 2227 - E.R. Gauthier, Ph.D.
Structure of the 20 amino acids1. Hydrophobic amino acids CHMI 2227 - E.R. Gauthier, Ph.D.
Structure of the 20 amino acids2. Aromatic amino acids CHMI 2227 - E.R. Gauthier, Ph.D.
Structure of the 20 amino acids2. Aromatic amino acids CHMI 2227 - E.R. Gauthier, Ph.D.
Structure of the 20 amino acids3. polar, uncharged amino acids CHMI 2227 - E.R. Gauthier, Ph.D.
In biochem: • oxidation: lose H • Reduction: gain H Disulfide bond Structure of the 20 amino acidsCysteine and cystine CHMI 2227 - E.R. Gauthier, Ph.D.
Ser PO4-3 ATP Protein kinase Protein phosphatase ADP H2O O- P=O O- Phospho-Ser Structure of the 20 amino acids Tyr, Ser, Thr CHMI 2227 - E.R. Gauthier, Ph.D.
Structure of the 20 amino acids4. Negatively charged amino acids CHMI 2227 - E.R. Gauthier, Ph.D.
100% D pH 9.5 pKa2 100% C pKaR 4.1 pKa1 A B C D 2.1 100% B pKa1 pKaR pKa2 What is the pI of glutamate? 100% A NaOH Structure of the 20 amino acids4. Negatively charged amino acids CHMI 2227 - E.R. Gauthier, Ph.D.
Structure of the 20 amino acids5. Positively charged amino acids CHMI 2227 - E.R. Gauthier, Ph.D.
pKa2 pKaR Structure of the 20 amino acids5. Positively charged amino acids: His CHMI 2227 - E.R. Gauthier, Ph.D.
Structure of the 20 amino acidspKa values of amino acids CHMI 2227 - E.R. Gauthier, Ph.D.
pH << pI pH >> pI + + Elution Analysis of amino acids1. Ion exchange chromatography CHMI 2227 - E.R. Gauthier, Ph.D.
O R-HC=O O O CO2 OH COO- OH N H NH3+ C O 2 R O O Amino acid Ninhydrin Purple!! Analysis of amino acids2. Detection of amino acids: ninhydrin reagent CHMI 2227 - E.R. Gauthier, Ph.D.