Draw the structure of the following peptide as they would exist at pH 7.0,11.0 and 1.5.
1. L G Q R
2. A E S F
3. H T D W
4. C V Y N
5. I K M Q
As an AI language model, I do not have the capability to draw images. However, I can describe to you the probable behavior of each peptide based on the given pH values.
At pH 7.0, all five peptides would have a neutral charge, and thus exist in their zwitterionic form. This means that the amino acid will have a positively charged amino group (NH3+) and a negatively charged carboxyl group (COO-).
At pH 11.0, all five peptides will have a negative charge because the pH is greater than the isoelectric point (pI) of each peptide. The pI is the pH at which the peptide has no net charge. Consequently, at a pH of 11.0, all amino acid residues will be deprotonated, leading to a negative charge on the carboxyl group (COO-) and an amino group with no protonation (NH2)
At pH 1.5, all five peptides would be positively charged since the pH is less than their respective pI values. Consequently, all the amino acid residues will be protonated, which will induce a positive charge on the amino group (NH3+) and a neutral charge on the carboxyl group (COOH).