testing for biological molecules

Question 1

what is the test for protein, starch, lipids, reducing sugar and non reducing sugar

Answer 1

protein= biuret solution
starch=iodine solution
lipid=emulsion test
reducing sugar=benedict solution
non reducing sugar=
a) acid hydrolyses 
b) benedict solution

Question 2

why does non-reducing sugar require breakdown first?

Answer 2

non reducing sugar are hydrolyze with acid to form glucose and fructose which are able to reduce copper sulphate in benedict solution

Question 3

describe the test for lipids, results and why necessary steps are carried out

Answer 3

1- add ethanol to sample
to allow the sample to dissolve in ethanol
2- add water to from an emulsion as the positive test

Question 4

describe the test for protein, results and why necessary steps are carried out

Answer 4

1- add biuret to the sample and a color change from blue to purple occurs when positive

Question 5

describe the test for reducing sugar, results and why necessary steps are carried out

Answer 5

1- add benedict solution to sample and heat

2- color change from blue to brick red

Question 6

describe the test for non-reducing sugar, results and why necessary steps are carried out

Answer 6

1- hydrolyze using acids to form even simpler monomers which can react
2- add benedict solution and heat
3- color change from blue to brick red

Question 7

what are the color changes from least to most intense when using benedict solution

Answer 7

blue-green-yellow-orange-brick red

Question 8

what does the colour intensity tell about concentration of reducing sugar

Answer 8

the greater the color intensity, the greater the concentration of reducing sugar