BIOL I 100-3
In this practical the composition of several unknown dipeptides was found using paper chromatography. This is a partition chromatography technique where cellulose in the form of paper acts as a hydrophilic support medium or liquid stationary phase where those aminoacids with polar side chains will interact. A second mobile phase containing water and a non polar solvent was used, the paper was introduced in a chromatography tank where the non polar solvent moved up the paper by capillary action, those amino acids with non polar side chains will move up the paper whereas, as it was said before, those with polar chains will interact with the hydrophilic stationary phase moving up the paper slightly.
The native unknown dipeptide and a hydrolised form of it were compared to six standard aminoacids to find out which were the components of the dipeptide. The hydrolised form will be separated into its constituent peptide residues. The results obtained were:
In the case of dipeptide HA it can be seen that the aminoacid which moves further up is leucine which has a non polar chain:
In this practical the composition of several unknown dipeptides was found using paper chromatography. This is a partition chromatography technique where cellulose in the form of paper acts as a hydrophilic support medium or liquid stationary phase where those aminoacids with polar side chains will interact. A second mobile phase containing water and a non polar solvent was used, the paper was introduced in a chromatography tank where the non polar solvent moved up the paper by capillary action, those amino acids with non polar side chains will move up the paper whereas, as it was said before, those with polar chains will interact with the hydrophilic stationary phase moving up the paper slightly.
The native unknown dipeptide and a hydrolised form of it were compared to six standard aminoacids to find out which were the components of the dipeptide. The hydrolised form will be separated into its constituent peptide residues. The results obtained were:
In the case of dipeptide HA it can be seen that the aminoacid which moves further up is leucine which has a non polar chain:
On the other hand tryphtophane is slightly more hydrophilic because of the presence of an amine group on its side chain:
Overall, amino acids side chains are very important to determine the properties of a protein affecting the way they fold and their structure.
The side chain of tryptophan has aromatic rings, which make it fairly nonpolar, rather than hydrophilic. Also, I think that you might have too much about the background - its not incorrect but just not necessary for these.
ReplyDelete/Steve