Science, asked by sauravchauhan5072, 6 months ago

Analogy Type:
1. Starch test: Iodine solution :: Sugar test:​

Answers

Answered by duvarakesh222K
2

Answer:

Aim

To carry out appropriate tests to detect the presence of sugar(sucrose), starch, proteins, and fats in suitable animal and plant materials.

Theory

Nutrition is a source through which living entities obtain food for the body to get fueled with energy. Therefore the food we eat must be well-balanced with all the substances that are required by our body to perform daily activities, these substances are known as nutrients.

Nutrients nourish the body by releasing the energy required for the body’s growth. Some of the nutrients found in food are:

Proteins

Carbohydrates

Fats

Vitamins

Minerals

Dietary fibers

What are proteins?

They are body-building nutrients which aid in the repair of damaged body parts and also in the growth of the body

What are vitamins and minerals?

These nutrients are reflected to be protective food. They protect us from diseases by providing resistance against germs that are known to cause diseases.

What are carbohydrates?

Carbohydrates are nutrients that provide energy to the body instantly. Fats are also energy-giving foods and store energy.

Carbohydrates contain starch, sugars, and fibres which consist of sugar molecules containing hydrogen, carbon, and oxygen. Carbohydrates can be categorized into:

Simple carbohydrates – They are composed of 1 or 2 units of sugar, hence can be broken down and be absorbed easily. Simple carbohydrates are subdivided into:

Monosaccharides – Composed of one sugar unit

Disaccharides – Consists of 2 chemically-associated monosaccharide units. Example – Lactose, Maltose, Sucrose, etc.

Complex carbohydrates – consists of long chains of simple carbohydrate units. Since they are large in size they can be broken down into simple carbohydrates. They are further subdivided into

Oligosaccharides – Composed of less than 10 monosaccharides parts

Polysaccharides – composed of a large number of polysaccharides. Example – Glycogen, starch, and cellulose

Test For Sucrose

The presence of sucrose can be tested in a sample using Benedict’s test.

Material Required

Benedict’s Reagent

Sugar cane extract

Concentrated HCl

NaOH solution

Burner

Dropper

Test-tube

Test tube holder

Procedure

Take a clean and dried test-tube and add sugar cane extract into it.

Now carefully add a few drops of concentrated HCl using a dropper to the test tube.

Hold the test tube securely with the help of a test tube holder.

Place the test tube near the Bunsen burner and allow the solution to boil for two minutes.

While boiling, the hydrolysis of sucrose occurs and the fructose converts to glucose.

With the help of a dropper, add a few drops of NaOH solution to the test tube so as the solution turns alkaline.

Now add a few drops of Benedict’s reagent with the help of a dropper into the test tube.

With the help of a test tube holder, place the test tube near the Bunsen burner and allow the solution to boil for a few minutes.

Observe the changes.

Observation

The colour of the solution colour from blur colour to green colour. From green colour, it finally changes to brick red or orange colour. This indicates that the solution contains glucose.

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.

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