The Amino Acid L-Lysine Has the Amine Side Chain R

Multiple Choice

The amino acid L-lysine has the amine side chain R = −(CH₂) ₄NH₂.At low pH,all ionizable groups are protonated.What is the net charge on this fully protonated form of L-lysine?

A) 2
B) 1
C) −1
D) −2
E) 0