Testing For Biological Molecules: Non- Reducing sugars.,

Question 1

What is 1 point about testing non-reducing sugars?

Answer 1

= cannot test it directly- you need to break the glycocidic bond to convert into a monosaccharide.
= then use benedicts test.

Question 2

If we want to test a solution for non-reducing sugars what do we do?

Answer 2

= check if the solution has reducing sugars
= take the benedicts solution test
= note colour change

Question 3

What is the second step we do?

Answer 3

= take a fresh boiling tube and add 3cm^3 of unknown solution
= add 3cm^3 of dilute hyrdochloric acid
= boil the solution gently in a hot water bath for 5 minutes.

Question 4

If a non-reducing sugar is present what happens?

Answer 4

= acid hydrolisises the gluycocid bonds
= releases monosacharides
= add 3cm^3 of filute alkaliae (sodium hydroxide)
= use PH paper to check if the solution is alkalai
= benedicts cannot work under acidic conditions

Question 5

What is the final step of this practical?

Answer 5

= add 3cm^3 of benedicts solution
= heat in boiling water for 5 minutes
= note color change
=