The substituents R1 and R2 for nine peptides are listed in the table g

The substituents R1 and R2 for nine peptides are listed in the table given below. How many of these peptides are positively charged at pH=7.0? Peptide R1 R2 I H H II H CH3 III −CH2COOH H IV −CH2CONH2 (CH2)4NH2 V −CH2CONH2 −CH2CONH2 VI (CH2)4NH2 (CH2)4NH2 VII −CH2COOH −CH2CONH2 VIII −CH2OH (CH2)4NH2 IX (CH2)4NH2 CH3

Answer» The substituents

R_{1}

and

R_{2}

for nine peptides are listed in the table given below. How many of these peptides are positively charged at pH=7.0?