#Question id: 176
#XL - T Zoology
A peptide has the sequence Glu–His–Trp–Ser–Gly–Leu–Arg–Pro–Gly. What is the net charge of the molecule at pH 3
#Question id: 177
#XL - T Zoology
The titration curve of alanine shows the ionization of two functional groups with pKa values of 2.34 and 9.69, corresponding to the ionization of the carboxyl and the protonated amino groups, respectively. The titration of di-, tri-, and larger oligopeptides of alanine also shows the ionization of only two functional groups, although the experimental pKa values are different. The trend in pKa values is summarized in the table. Which of the following is a reason for this shift in pK values
#Question id: 178
#XL - T Zoology
Given the pKa values of different acidic sites in cysteine, the principal ionic form which will never exist at any pH
#Question id: 180
#XL - T Zoology
Which of the following statements about aromatic amino acids is correct?
#Question id: 181
#XL - T Zoology
Titration of valine by a strong base, for example NaOH, reveals two pK’s. The titration reaction occurring at pK2 (pK2 = 9.62) is:
#Question id: 182
#XL - T Zoology
Which amino acid is least likely to participate in acid-base catalysis?