Chapter 7.1: Monosaccharides and Disaccharides

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Chapter 7.1 Monosaccharides and Disaccharides

• CHEM 7784
• Biochemistry
• Professor Bensley

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CHAPTER 7.1 Monosaccharides and Disaccharides
Todays Objectives (To learn and understand
the)

• Structures and names of monosaccharides
• Open-chain and ring forms of monosaccharides
• Structures and properties of disaccharides

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Aldoses and Ketoses

• An aldose contains an aldehyde functional group
• A ketose contains a ketone functional group

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Enantiomers

• D-glucose and L-glucose are ENANTIOMERS
  non-superimposable COMPLETE mirror images (differ
  in configuration at EVERY CHIRAL CENTER).

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Diastereomers
D-Threose
D-Erythrose
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Epimers

• Epimers are two sugars that differ only in the
  configuration around one carbon atom

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Structures to Know

• Ribose is the standard five-carbon sugar
• Glucose is the standard six-carbon sugar
• Galactose is an epimer of glucose
• Mannose is an epimer of glucose
• Fructose is the ketose form of glucose

D-Ribose D-Glucose D-Galactose D-Mannose D-Fructos
e
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Hemiacetals and Hemiketals
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Cyclization of Mono- saccharides
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Pyranoses and Furanoses
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Chain-ring Equilibrium and Reducing Sugars
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Important Hexose Derivatives
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The Glycosidic Bond
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Nonreducing Disaccharides

• Two sugar molecules can be also joined via a
  glycosidic bond between two anomeric carbons
• The product has two acetal groups and no
  hemiacetals
• There are no reducing ends, this is a nonreducing
  disaccharide
• Examples Sucrose and Trehalose (structures on
  next slide)

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Common Disaccharides