non-reducing sugars

Question 1

how do you test for non-reducing sugars directly

Answer 1

you are not able to

Question 2

what do we do instead of directly testing for non-reducing sugars

Answer 2

break the glycosidic bond releasing the monosaccharides

Question 3

because all monosaccharieds are reducing sugars what can we do know we have released them

Answer 3

we can test for non-reducing sugars using benedicts solution

Question 4

what is the first step in finding a non reducing sugar

Answer 4

first check if the solution also has any reducing sugar by doing the benedicts test and take that information into account later on

Question 5

what is the second step in finding a non reducing sugar

Answer 5

next we take a fresh boiling tube and add 3cm^3 of our uknown solution

Question 6

what is the third step in finding a non reducing sugar

Answer 6

add 3cm^3 of dilute hydrochloric acid

Question 7

what is the fourth step in finding a non reducing sugar

Answer 7

gently boil the solution in a water bath for five minutes

Question 8

what is the fifth step in finding a non reducing sugar

Answer 8

if a non-reducing sugar is present the acid hydrolyses the glycosidic bonds releasing the monosaccharide

Question 9

what is the sixth step in finding a non reducing sugar

Answer 9

ad 3cm^3 of a dilute alkali and use pH paper to check our solution is alkaline

Question 10

what is an example of a dilute alkali

Answer 10

sodium hydroxide

Question 11

why ,must we check that our solution is alkali

Answer 11

as the benedicts test cannot work under acidic conditions

Question 12

what is the seventh step in finding a non reducing sugar

Answer 12

add 3cm^3 of benedicts solution and heat in boiling water for five minutes

Question 13

what must be noted any time something is poured into the solution

Answer 13

note the colour change