#Question id: 172
#Unit 1. Molecules and their Interaction Relevant to Biology
Which amino acid is least likely to participate in acid-base catalysis?
#Question id: 173
#Unit 1. Molecules and their Interaction Relevant to Biology
What is the net charge on the tripeptide Gly-Arg-Lys at pH 7? The table below gives the pKaʹs of the ionizable groups on the free amino acids.
#Question id: 174
#Unit 1. Molecules and their Interaction Relevant to Biology
What is the net charge on the dipeptide Arg-Pro at pH 9.0? The table below gives the pKaʹs of the ionizable groups on the free amino acids.
#Question id: 175
#Unit 1. Molecules and their Interaction Relevant to Biology
The ionic charges associated with a protein molecule are ________.
#Question id: 176
#Unit 1. Molecules and their Interaction Relevant to Biology
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
#Unit 1. Molecules and their Interaction Relevant to Biology
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