identification of sugar starch protein and fat through conduct of relevant tests
( for biology practical project please answer or send the complete practical)
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identification of sugar starch protein and fat through conduct of relevant tests
( for biology practical project please answer or send the complete practical)
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Answer:
Test For Starch
Material Required
Potato extract
Iodine solution
Test tube
Dropper
Procedure
Take a clean and dried test-tube and add potato extract into it.
Add five to six drops of iodine solution with the help of a dropper into the test tube.
Keep the test tube undisturbed and allow the mixtures to stand for a few seconds.
Observe the changes.
Observation
The presence of starch in the potato extract is indicated when the colour changes to a blue-black colour.
Test For Proteins
The presence of proteins in a sample can be detected by the following tests:
Biuret Test
Xanthoproteic Test
Million’s Test
1. Biuret Test
Material Required
1% CuSO4
40% NaOH solution
Dropper
Egg Albumin
Test tube
Test tube holder
Procedure
Take a clean and dried test-tube and add egg albumin into it.
Now add a few drops of 40% NaOH solution with the help of a dropper into the test tube containing the egg albumin.
With the help of a dropper, add 2 to 3 drops of 1% CuSO4 solution into the same test tube contained in the egg albumin.
Now shake the test tube slowly in order to mix the solution present in it completely.
Keep the test tube undisturbed and allow the mixtures to stand for 5 minutes. After a few minutes, observe the changes.
Observation
The solution in the test tube appears to be violet in colour. This indicates that the sample that is tested contains proteins.
2. Xanthoproteic Test
Material Required
Ammonia solution
Concentrated HNO3
Dropper
Test tube
Egg albumin
Test tube holder
Procedure
Take a clean and dried test-tube and add egg albumin into it.
Add five drops of concentrated HNO3 with the help of a dropper into the test tube containing the egg albumin.
Holding the test tube securely with a test tube holder, bring the sample to a boil over a burner.
As the solution starts to boil, a yellow precipitate is formed.
Now add a few drops of ammonia solution into the test tube slowly.
Stir the test-tube continuously in order to mix the solution completely. After a few minutes, observe the changes.
Observation
The sample contained in the test tube, which appeared to have yellow precipitate changes its colour to orange. This indicates that the sample contains proteins.
3. Million’s Test
Materials Required
Million’s Reagent
Egg albumin
Test tube
Dropper
Procedure
Take a clean and dried test-tube and add egg albumin into it.
With the help of a dropper, add a few drops of the Million’s reagent into the test tube containing the egg albumin.
Keep the test tube undisturbed and allow the mixtures to stand for 5 minutes.
After a few minutes, observe the changes.
Observation
The sample indicates the presence of proteins when the colour changes to pink.
Test For Fats
The presence of fats in a sample can be detected by the following tests:
Sudan III Test
Paper Spot Test
1. Sudan III Test
Materials Required
Sudan III Solution
Oil
Test tube
Dropper
Egg Albumin
Procedure
Take a clean and dried test-tube and add a few drops of oil into it.
Now into the same test tube, add five to six drops of the Sudan III reagent with the help of a dropper.
Stir the test tube continuously and allow the solution to stand for a while.
After a few seconds, observe the changes.
Observation
The presence of fat in the sample is indicated when pink colour droplets appear on the test tube.
2. Paper Spot Test
Materials Required
A piece of white paper
Peanut seeds
Watch glass
Procedure
On the piece of white paper, place the fresh peanut seeds.
Crush and rub the peanut seeds in the white paper.
Remove the peanut seed remaining on the watch glass.
Observe the changes on the piece of white paper.
Observation
The spot where the peanut seeds are rubbed turns translucent. This indicates the presence of fats in the sample.
Identification of sugar starch protein and fat through conduct of relevant tests