Answer: The charge on peptide chain lys-lys-his-glu at pH 7 is +1.
Explanation: A peptide chain is the chain formed from the condensation of two amino acids releasing [tex]H_2O[/tex] molecule and forming N-terminal(Nitrogen- end) and C-terminal(Carboxyl-end). The bonds formed are known as peptide bonds.
Here 4 amino acids join together forming a peptide chain
[tex]lys-lys-his-glu[/tex]
In this peptide chain N-terminal is from lysine (lys) and C-terminal is from Glutamic acid (Glu).
At pH=7,
So, there are 3 amino groups present each having (+1) charge and 2 carboxyl groups each having (-1) charge.
Total charge on peptide chain = [tex](3\times (+1))+(2\times (-1))[/tex]
= +1