World's only instant tutoring platform
dropdown-logo
Get 2 FREE Instant-Explanations on Filo with code FILOAPP
Biology
Biology

Class 11

NCERT

1

Chapter 1: The Living World

11 questions

arrow
2

Chapter 2: Biological Classification

12 questions

arrow
3

Chapter 3: Plant Kingdom

12 questions

arrow
4

Chapter 4: Animal Kingdom

15 questions

arrow
5

Chapter 5: Morphology of Flowering Plants

15 questions

arrow
6

Chapter 6: Anatomy of Flowering Plants

12 questions

arrow
7

Chapter 7: Structural Organization in Animals

14 questions

arrow
8

Chapter 8: Cell: The Unit of Life

14 questions

arrow
9

Chapter 9: Biomolecules

15 questions

10

Chapter 10: Cell Cycle and Cell Division

16 questions

arrow
11

Chapter 11: Transport in Plants

16 questions

arrow
12

Chapter 12: Mineral Nutrition

10 questions

arrow
13

Chapter 13: Photosysnthesis in Higher Plants

9 questions

arrow
14

Chapter 14: Respiration in Plants

12 questions

arrow
15

Chapter 15: Plant Growth and Development

11 questions

arrow
16

Chapter 16: Digestion and Absorption

15 questions

arrow
17

Chapter 17: Breathing and Exchange of Gases

14 questions

arrow
18

Chapter 18: Body Fluids and Circulation

14 questions

arrow
19

Chapter 19: Excretory Products and their Elimination

12 questions

arrow
20

Chapter 20: Locomotion and Movement

10 questions

arrow
21

Chapter 21: Neural Control and Coordination

12 questions

arrow
22

Chapter 22: Chemical Coordination and Integration

9 questions

arrow
Question
Medium
Timing Icon

Solving time: 10 mins

Find out a qualitative test for proteins, fats and oils, amino acids. Test any fruit juice, saliva, sweat and urine for them.

tutor 0tutor 1tutor 2
Found 7 tutors discussing this question
Discuss this question LIVE
15 mins ago

Text SolutionText solutionverified iconVerified

(a) Test for protein
Biuret’s test – If Biuret’s reagent is added to the protein, then the colour of the reagent changes from light blue to purple.
(b) Test for fats and oils 
Emulsion test - Add ethanol to a very small amount of the test substance. Shake in order to dissolve. Filter or dilute to obtain fairly clear liquid. Take another tube containing water and pour the ethanolic solution into the top. A white (milk like) emulsion indicates the presence of fats or oils.
(c) Test for amino acid
Ninhydrin test – If Ninhydrin reagent is added to the solution, then the colourless solution changes to pink, blue, or purple, depending on the amino acid.
1) Fruit juice 
Biuret’s test - Fruit juice + Biuret’s reagent -Colour changes from light blue to purple. Protein is present.
Grease test - To a brown paper, add a few drops of fruit juice - No translucent spot. Fats and oils are absent or are in negligible amounts
Ninhydrin test - Fruit juice + Ninhydrin reagent + boil for 5 minutes - Colourless solution changes to pink, blue, or purple colour. Amino acids are present.
2) Saliva
Biuret’s test - Saliva + Biuret’s reagent - Colour changes from light blue to purple. Proteins are present.
Grease test - On a brown paper, add a drop of saliva - No translucent spot. Fats/oils are absent.
Ninhydrin test - Saliva + Ninhydrin reagent + boil for 5 minutes - Colourless solution changes to pink, blue, or purple colour. Amino acids are present.
3) Sweat
Biuret’s test - Sweat + Biuret’s reagent- No colour change. Proteins are absent.
Solubility test - Sweat + Water - Oily appearance - Fats/oil may be present.
Ninhydrin test - Sweat + Ninhydrin reagent + boil for 5 minutes - No colour change, the solution remains colourless. Amino acids are absent.
4) Urine
Biuret’s test - Few drops of urine + Biuret’s reagent - Colour changes from light blue to purple- Proteins are present.
Solubility test - Few drops of urine + Water - Little bit of oily appearance. Fats may or may not be present.
Ninhydrin test - Few drops of urine + Ninhydrin reagent + boil for 5 minutes. Colourless solution changes to pink, blue, or purple colour depending on the type of amino acid- Amino acids are present.
Was this solution helpful?
55
Share
Report
One destination for complete JEE/NEET preparation
One destination to cover all your homework and assignment needs
Learn Practice Revision Succeed
Instant 1:1 help, 24x7
Instant 1:1 help, 24x7
60, 000+ Expert tutors
60, 000+ Expert tutors
Textbook solutions
Textbook solutions
Big idea maths, McGraw-Hill Education etc
Big idea maths, McGraw-Hill Education etc
Essay review
Essay review
Get expert feedback on your essay
Get expert feedback on your essay
Schedule classes
Schedule classes
High dosage tutoring from Dedicated 3 experts
High dosage tutoring from Dedicated 3 experts
Trusted by 4 million+ students
filo Logo
Doubt Icon Doubt Icon

Stuck on the question or explanation?

Connect with our Biology tutors online and get step by step solution of this question.

231 students are taking LIVE classes
Question Text
Find out a qualitative test for proteins, fats and oils, amino acids. Test any fruit juice, saliva, sweat and urine for them.
TopicBiomolecules
SubjectBiology
ClassClass 11
Answer TypeText solution:1
Upvotes55