Home
NCERT Solution
Class 11
Biology
Biomolecules
find out a qualitative test for proteins fats and...

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

Answer:

(a) Test for protein

Biuret’s test – If Biuret’s reagent is added to protein, then the colour of the reagent changes from light blue to purple.

(b) Test for fats and oils

Grease or solubility test

(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.

Item		Name of the test	Procedure	Result	Inference
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, 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.

1
0
0
Report?

Report a problem on Specifications:

Email id:

Comments

Next Question >

SELECT ex_no,question,question_no,id,chapter FROM question_mgmt as q WHERE courseId='2' AND subId='7' AND ex_no!=0 AND status=1 and id!=279 ORDER BY views desc, last_viewed_on desc limit 0,10

Popular questions of class 11 Biology

Q: Describe briefly the four major groups of Protozoa.

Q: Why are living organisms classified?

Q: State two economically important uses of: (a) Heterotrophic bacteria (b) Archaebacteria

Q: What is the difference between direct and indirect development?

Define a taxon. Give some examples of taxa at different hierarchical levels.

Q: Describe the important properties of enzymes.

What are the steps involved in formation of a root nodule?

Q: Illustrate the taxonomical hierarchy with suitable examples of a plant and an animal.

Q: How is a key helpful in the identification and classification of an organism?

Q: What is stomatal apparatus? Explain the structure of stomata with a labelled diagram.

SELECT ex_no,question,question_no,id,chapter FROM question_mgmt as q WHERE courseId='2' AND subId='7' AND ex_no!=0 AND status=1 and id!=279 ORDER BY last_viewed_on desc limit 0,10

Recently Viewed Questions of Class 11 Biology

Choose the correct answer among the following:
(a) Gastric juice contains
(i) pepsin, lipase and rennin
(ii) trypsin lipase and rennin
(iii) trypsin, pepsin and lipase
(iv) trypsin, pepsin and renin
(b) Succus entericus is the name given to
(i) a junction between ileum and large intestine
(ii) intestinal juice
(iii) swelling in the gut
(iv) appendix

Q: Describe the important properties of enzymes.

Q: Explain with examples: macronutrients, micronutrients, beneficial nutrients, toxic elements and essential elements.

Write the difference between:
(a) Actin and Myosin
(b) Red and White muscles
(c) Pectoral and Pelvic girdle

Q: Write true or false. If false change the statement so that it is true.
(a) Actin is present in thin filament
(b) H-zone of striated muscle fibre represents both thick and thin filaments.
(c) Human skeleton has 206 bones.
(d) There are 11 pairs of ribs in man.
(e) Sternum is present on the ventral side of the body.

Q: Define the following terms:
(a) Aestivation
(b) Placentation
(c) Actinomorphic
(d) Zygomorphic
(e) Superior ovary
(f) Perigynous flower
(g) Epipetalous Stamen

Q: RuBisCo is an enzyme that acts both as a carboxylase and oxygenase. Why do you think RuBisCo carries out more carboxylation in C4plants?

Q: Describe the internal structure of a dorsiventral leaf with the help of labelled diagrams.

Q: Explain the autoregulatory mechanism of GFR.

Q: What will be the pO2 and pCO2 in the atmospheric air compared to those in the alveolar air?
(i) pO2 lesser, pCO2 higher
(ii) pO2 higher, pCO2 lesser
(iii) pO2 higher, pCO2 higher
(iv) pO2 lesser, pCO2 lesser

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

< Previous Question

Next Question >

Popular questions of class 11 Biology

Recently Viewed Questions of Class 11 Biology

Comments

Comment(s) on this Question

Important links

Quick Links

Resources

Support