You are evaluating the pH-dependent properties of the peptide R-E-T-C-H. You do NOT need to draw the peptide on this exam, but it will be to your advantage to sketch out a schematic image of it to account for the effects of pH on charges of individual groups. What is the net charge on the peptide at pH 7.0? Show how you reached your conclusion with calculations, but please circle your answer so that it can be clearly seen – even if you do calculations on a separate page. Please use the pKa values that we used in class for the N- [8.0] and C- [3.0] termini and for the amino acid side chains. When calculating the charge per group, you can consider any group fully (de)protonated when it is >2.0 pH units from its pKa – but anything 2.0 pH units must be calculated specifically.