Question

What is procedure to test proteins ​

Answer 1

Answer:

$\sf\huge\bold\red\mid\blue{\underbrace{\overline{\textbf{✿❤ ᴀɴꜱᴡᴇʀ❤✿}}}}$

Biuret solution is used to identify the presence of protein. Biuret reagent is a blue solution that, when it reacts with protein, will change color to pink-purple.

•••••••♣•••••••••♣•••••••••♣•••••••••♣•••••••

Brainlieast = 10 Thanks❤️

Answer 2

Answer: A Biuret test is a chemical test used to determine the presence of a peptide bond in a substance. It is based on the biuret reaction in which a peptide structure containing at least two peptide links produces a violet color when treated with alkaline copper sulfate. In presence of an alkaline solution, blue-colored copper II ion can form a complex with the peptide bonds since the peptide has unshared electron pairs in nitrogen and oxygen of water. The colored coordination complex is formed between Cu2+ ion and carbonyl oxygen (>C=O) and amide nitrogen (=NH) of the peptide bond. Once this complex has been formed, the solution turns from blue to purple. The deeper the purple color, the higher is the number of peptide-copper complexes. The reaction occurs in any compound containing at least two H2N-C, H2N-CH2-, H2N-CS- or similar groups joined together directly or through a carbon or nitrogen atom. One copper ion is probably linked to 6 nearby peptide linkages by co-ordinate bonds. The intensity of the color is directly proportional to the number of the peptide bonds present in the protein molecule that is reacting and also the number of the protein molecules present in the reaction system.  The Biuret reagent is a solution composed of sodium hydroxide (NaOH) or potassium hydroxide (KOH), hydrated copper (II) sulfate, and potassium sodium tartrate. Sodium hydroxide and Potassium hydroxide provide the alkaline medium and potassium sodium tartrate is added to chelate and thus stabilize the cupric ions in the solution or to maintain their solubility in alkaline solution.

Biuret Test Procedure

Take 3 clean and dry test tubes.

Add 1-2 ml of the test solution, egg albumin, and deionized water in the respective test tubes.

Add 1-2 ml of Biuret reagent to all the test tubes.

Shake well and allow the mixtures to stand for 5 minutes.

Observe for any color change.

Biuret Test Uses

Biuret reaction with protein is applicable to the quantitative determination of total protein by spectrophotometric analysis.

Hope it help.......