Biochem Exam 3

  1. Carbohydrates
    Carbon hydrates, with a rough chemical composition of (C*H20)n
  2. Saccharides
    • Sugar
    • Optically active and chiral
  3. Monosaccharide
    Monomer unit of a sugar molecule
  4. Oligosaccharide
    Small polymer of monosaccharides
  5. Polysaccharide
    Larger polymer of monosaccharide groups linked together
  6. Glycoprotein
    Oligosaccharides linked to protein
  7. Glycolipid
    Oligosaccharides linked to lipids
  8. Ketose
    Keytone as the carbonyl groupImage Upload 1
  9. Aldose
    • Aldehyde as the carbonyl group
    • Image Upload 2
  10. How to determine D- or L-
    Image Upload 3
  11. Most common enantiomer of sugar
    D-sugars
  12. Epimers
    • Molecules (sugars) are identical except rotation around one asymmetric carbon
    • Image Upload 4
  13. Image Upload 5
    D-Glyceraldehyde

    Aldotriose
  14. Image Upload 6
    D-Erythrose

    Aldotetroses
  15. Image Upload 7
    D-Ribose

    Aldopentoses
  16. Image Upload 8
    D-Xylose

    Aldopentoses
  17. Image Upload 9
    D-Galactose

    Aldohexoses
  18. Image Upload 10
    D-Mannose

    Aldohexoses
  19. Image Upload 11
    D-Glucose

    Aldohexoses
  20. Image Upload 12
    Dihydroxyacetone

    Ketotriose
  21. Image Upload 13
    D-Erythrulose

    Ketotetrose
  22. Image Upload 14
    D-Ribulose

    Ketopentoses
  23. Image Upload 15
    D-Xylulose

    Ketopentoses
  24. Image Upload 16
    D-Fructose

    Ketohexoses
  25. Furanose
    • Sugars with a 5-membered ring
    • Image Upload 17
  26. Pyranose
    • Sugars with a 6-membered ring
    • Image Upload 18
  27. How do sugar molecules convert from their linear form to a ring structure?
    By nuc attack of the carbonyl by an alcohol to form either a hemiacetal or hemiketal

    In this, the carbonyl becomes a new stereo center and is referred to as the anomeric carbon (C*)
  28. Hemiacetals vs Hemiketals
    Image Upload 19
  29. Alpha anomers
    • Image Upload 20
    • OH is pointing down
  30. Beta anomers
    • Image Upload 21
    • OH is pointing up
  31. Mutarotation
    Conversion between alpha and beta anomers
  32. Haworth Projections
    Simplified method of drawing ring structures with the plane of the ring perpendicular to the page (not geometrically precise)
  33. Image Upload 22
    Alpha-D-Glucofuranose

    Beta-D-Glucofuranose
  34. Fructose Cyclization
    • Fructose forms furanose and pyranose¬†
    • Image Upload 23
    • Image Upload 24
  35. Reducing sugars
    • Aldehyde group may act as a reducing agent and may oxidized to carboxylic acid
    • Sugar containing an aldehyde group is called this
  36. Aldonic Acids
    Aldehyde oxidized to carboxylic acid
  37. Uronic acids
    Primary alcohol oxidized to carboxylic acid
  38. Alditols
    • Aldehyde and ketone groups can be reduced under mild conditions to yield this
    • Image Upload 25
  39. Xylitol
    Popular sugar alcohol that is used as sweetener in chewing gum
  40. Glycosidic bonds
    • Any bonding of the sugar anomeric group (alpha or beta form) generates this
    • After the anomeric alcohol reacts, the glycosidic bond is stable and the anomers can no longer interconvert by mutarotation
  41. Glycosidases
    Enzymes which selectively cleave glycosidic bonds are required to break the formed bond
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Zaqxz
ID
349445
Card Set
Biochem Exam 3
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