Question

The molecule pictured below produced a blue color when tested with Benedict’s reagent, a yellow color when tested with IKI, and a violet color when tested with Biuret reagent. Based on the structure shown below and these chemical results, what kind of biomolecule is this? the molecule a blue color with benedicts reagent.no color change that given molecule is not a simple carbohydrate

Answer 1

The molecule is a protein

Step-by-step explanation:

When the molecule was tested with benedict's solution and a blue color was formed, that actually meant there was no colour change because the colour of benedict's solution is blue. Benedict's solution is used to test for the presence of reducing sugar, which changes it's colour to green, orange, yellow or even red; the fact that there was no colour change shows the molecule is not a reducing sugar.

Yellow colour when tested with IKI (Iodine-potassium iodide) also shows no colour change. IKI reagent is used to determine the presence of starch, which gives off a dark-blue colour if starch is present. Hence, absence of this dark-blue colour or observation of a yellow/orange colour shows the molecules is not starch.

Biuret reagent is used to test for peptide bonds in a molecule. In the presence of a peptide bond, the biuret reagent changes colour from blue to violet. The amino acids in proteins are held together by peptide bond, hence the biuret colour change shows that the biomolecule is a protein.