1.3 Carbohydrates - Disaccharides & Polysaccharides Flashcards
1
Q
glucose + glucose =
A
maltose
2
Q
glucose + fructose =
A
sucrose
3
Q
glucose + galactose =
A
lactose
4
Q
What is a condensation reaction?
A
When monosaccharides join, and a molecule of water is removed, forming a glycosidic bond
5
Q
What is a hydrolysis reaction?
A
The breakdown of polymers into monomers, by water
6
Q
What is the test for non-reducing sugars?
A
- Benedict’s test first
- add another 2cm food sample to 2cm dilute HCl acid
- place in test tube in water bath for 5 mins
- ## re-test; add 2cm Benedict’s reagent in water bath for 5 mins
7
Q
Why do we use dilute HCl acid for the reducing sugars test?
A
HCl acid will hydrolyse any present disaccharides into monosaccharides.
8
Q
What are polysaccharides?
A
Polymers formed by combining together many monosaccharide molecules, joined by glycosidic bonds
9
Q
What is the test for starch?
A
- 2cm of sample in test tube
- 2 drops of iodine solution
- starch present = blue-black
