1.2.7 - Biochemical tests Flashcards
1
Q
Test for reducing sugars
A
Add benedict’s solution containing copper 2+ ions
Heat in a water bath at 90
The reducing sugar reacts with the benedict’s and reduces copper 2+ to 1+
Colour change from blue to orange/red
2
Q
test for non reducing sugars
A
Heat with a few drops of HCl
neutralise with hydrogen carbonate
Produces sugars which are monosaccharides which will give a positive benedicts test
3
Q
Why do you heat with Hcl when testing for non reducing sugars?
A
Hydrolyses glycosidic bonds
4
Q
test for protein
A
Add biuret solution
will turn violet
5
Q
test for starch
A
Add iodine solution
will turn blue/black
6
Q
test for lipids
A
Add ethanol and shake
will turn a cloudy white colour
