Question

Modify lysine, below, to show the predominant form at pH 7.

Answer 1

The pH 7, suggests neutral state, that is, no proton in the solution. Its composition is given in the attachment below.

At pH = 7, Lysine possess net charge of +1. The isoelectric point of lysine is 9.75. Thus, its shows +1 net charge, it is actually a fractional charge.

Answer 2

Basically, both amine groups will be pronated while the carboxylic acid will be depronated due to their pkas.