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.
When biuret reagent is added to egg white (protein), the solution turns lilac or purple.
Biuret reagent is used to test for protein in urine. It is a common test that students in biology class perform. Urine is added to a test tube, followed by approximately the same amount of Biuret reagent. If the solution turns lavender this means that there are proteins present in the urine.
the test is to determine if the substance you are testing has protein in it
Use Biuret reagent.
copper(II) ions + protein (2 or more peptide bonds) ---> biuret complex (PURPLE!) the intensity of the purple depends on how many copies of the complex have been formed.
yes
biuret reagent
Biuret reagent is used to test for protein in urine. It is a common test that students in biology class perform. Urine is added to a test tube, followed by approximately the same amount of Biuret reagent. If the solution turns lavender this means that there are proteins present in the urine.
The Biuret reagent can be used.
the test is to determine if the substance you are testing has protein in it
Biuret reagent test in a practical situation tests for lipids. Biuret is used in food agents for protein amino acid chains.
Use Biuret reagent.
No, it changes lavenderish when protein is present.
Biuret reagent detect peptide bonds.
Buiret Reagent
If Biuret Reagent is related to the presence of Protein macromolecules, then a positive result will change it's colour from blue to violet.
food that has protein like milk will cause the Biuret solution to turn purple.
A positive test, when using Biuret reagent, would be purple-ish