Sugars Flashcards

1
Q

Reducing Sugar

A
  • sugars that can donate an electron.
    - donates an electron to
    reduce copper (ll) ions in
    copper sulphate solution,
    which is blue
    - Cu (ll) ions are reduced to
    Cu (l) ions, in red copper
    (l) oxide
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2
Q

Testing for the presence of sugars

A
  • equal volume of benedict’s solution and the solution being tested are boiled.
  • if a reducing sugar is present, e.g. glucose, the solution will change colour from blue to brick-red
  • described as a qualitative test, as it doesn’t give the actual concentration of the reducing sugar
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3
Q

Non-reducing sugars

A

Some disaccharide, e.g. sucrose cannot be detected by the benedict’s solution unless their broken down into their constituent monosaccharides.

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4
Q

Testing for a non-reducing sugar

A

-Hydrochloric acid is added to the solution being tested.
- Alkali is added
- Benedict’s solution is added, and the solution is boiled
- If the solution turns red, a non-reducing sugar was initially present.

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