Question

If you boil a protein in hydrochloric acid it will break down to its constituent amino acids. Assume that you had done this to a typical protein and then had spotted these amino acids to a spot on the chromatograph. What pattern would you expect to see at the end of the experiment? Explain your prediction.

Answer 1

Upon boiling with HCl, proteins break down into corresponding amino acids. Thus the reaction mixture contains a mixture of amino acids.

Chromatograhy is an analytical tool to distinguish different biomolecules. It consists of chromatographic paper which consists of mostly cellulose. biomolecules are spotted on the paper and dipped it in an organic solvent. the organic solvent is drawn up in this paper through capillary action. If the solvent moves over the biomolecule, the biomolecule starts to move along with the solvent. the rate of movement of biomolecule depends on the affinity of it with the paper. hydrophobic molecules move fast because they are more attracted by the hydrophobic solvent than hydrophilic paper.

At the end of this experiment, we can see different spots on the chromatographic paper in which each spot corresponding to different amino acid. The difference in the rate of amino acids movement is due to the difference in the alkyl group present in it. The Rf value of each spot is compared with the standard value and by this, we can identify each amino acid formed after the reaction.