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Why both cows milk and water-buffalos milk produce a violet colour when tested with biuret solution?
Wiki User
∙ 6y ago
Both cows milk and water-buffalo's milk produce a violet colour when tested with biuret solution because they both contain protein.
Zencsy
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What is the function of alkaline solution in Biuret's test?
Alkaline levels are essential for the solution to change colour. Without alkaline levels, the colour of the solution would not be detectable.
What does biuret solution specifically react with to produce a color change?
Copper sulphate gives biuret reagent it's blue colour.
What colour is biuret before test?
Blue!!
What are the conclusions from testing the Biuret reagent for protein?
The reagent used in the Biuret Test is a solution of copper sulfate (CuSO4) and potassium hydroxide (KOH). The KOH is there to raise the pH of the solution to alkaline levels; the crucial component is the copper (II) ion from the CuSO4. When peptide bonds are present in this alkaline solution, the copper (II) ions will form a coordination complex with four nitrogen atoms involved in peptide bonds. Copper Sulfate solution is a blue colour, but when the copper (II) ions are coordinated with the nitrogen atoms of these peptide bonds, the colour of the solution changes from blue to violet. This colour change is dependent on the number of peptide bonds in the solution, so the more protein, the more intense the change. When the peptides are very short, the solution turns a pink colour, rather than violet.
What is used to test for the presence of proteins?
non
How amylase breakdown starch?
To test starch: To test starch you take the food sample, and add iodine solution if the colour turns black this means starch is present. To test for protein: To test for protein, you take the food sample and add Biuret A and Biuret B and shake, if the colour turns lilac this means that protein is present.
What chemical reagent is used for proteins?
The biuret test tests for peptide (protein) bonds. In a test with a protein containing substance, a Copper(II) ion is reduced to Copper(I) which forms a compound with the nitrogen and carbon atoms of the peptide (protein) bonds in an alkaline (pH above 7) solution. If the solution goes to a purply-violet colour, proteins have been detected.
Solution contains metallic ion blue in colour flame test produce blue green colour The solution forms a precipitate when sodium hydroxide is added to the solution What is the ion in the solution?
Most likely copper.
How do you tell if a substance contains protein by using biuret test?
If Biuret Reagent is related to the presence of Protein macromolecules, then a positive result will change it's colour from blue to violet.
Would cysteine test positive in a biuret test?
no! no change in colour confirms presence of cysteine
What color does biuret turns if protein is present?
purple for longer peptides (larger proteins) and pink for shorter ones
Why do you swirl the Erlenmeyer flask?
To mix the reactants. Assuming you have been doing a titration experiment and I am doing your homework its so as you add the acid/alkali you can accuratly close the biuret when the indicator changes colour.
