Monosaccharides Flashcards
1
Q
What is a reducing sugar?
A
- Donates electrons
- Carbonyl group becomes oxidised
- Sugar is reducing agent
2
Q
How can we test for reducing sugars? Results?
A
- Benedict’s Test
- Soluble copper sulphate reduced
- To insoluble crick red copper oxide
3
Q
Examples of reducing sugars?
A
- Glucose
- Fructose
- Galactose
Fructose and galactose are isomers of each other, hence have different properties despite same molecular formula.
4
Q
What are non-reducing sugars? How are they tested for?
A
Cannot donate electrons, so cannot be oxidised.
They must be hydrolysed first into monosaccharide reducing sugars before tested for using the benedicts test. Eg. Sucrose.
5
Q
Difference between alpha and beta glucose?
A
Alpha : OH group on 1st carbon is below the ring.
Beta : OH group on 1st carbon is above the ring
6
Q
Examples of important pentose sugars. Difference in the 2?
A
- Ribose and deoxyribose
- Make up RNA and DNA
- Deoxyribose has 1 less Oxygen atom on carbon 2.
