Amino Acids

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Amino Acids
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Functions of Amino Acids

• 1. Building blocks of proteins
• 2. Modified amino acids are neurotransmitters,
  etc.

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Defined by Structure

• Standard amino acids are a-amino carboxylic acids

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Stereochemistry

• Naturally occurring amino acids are L-amino acids

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Classification of Amino Acids

• Polarity
• functional group
• acidic, basic or neutral

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Amino Acids are Charged at Physiological pH

• Zwitterion- and - regions net charge 0

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Amino Acid Properties

• Ionic- high mp, \ solid at room temp
• very water soluble
• tidbit avg mol wt 110

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Amino Acid Structures

• name and 3 letter abbreviation of all 20
• at phys pH

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Acid-base Chemistry

• R group dissociates in same manner
• Consider neutral, basic, acidic

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Neutral Amino Acid all but 5

• R group dissociates in same manner
• Consider pH 1, pH pKcarboxy, pH pI, pH
  pKamino, pH 13

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Other Amino Acid Chemistry

• Lab reactions ninhydrin and FDNB
• modified amino acids
• peptide bond formation

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Peptides

• Dipeptide
• Nomenclature

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Peptide Chemistry

• peptide bond cleavage
• acid or base
• some aa destroyed
• acid-base chemistry- R groups only
• pK data
• net charge used
• physiological activity
• almost unlimited examples