Determine the net charge of the predominant form of Asp at (a) pH 1.0, (b) pH 3.0, (c) pH 6.0, and (d) pH 11.0.

a) +1

b) 0

c) -1

d) -2

Explanation:

The aspartic acid is one of the twenty amino acids that make up proteins.

The equilibrium is in the image. pka for this molecule are 1.88, 3.65 and 9.60. A higher pH than pka will have as predominant form the molecule in the right and vice versa. The net charge in each molecule is in red.

Thus, for a pH of 1.0, as the pH is lower than first pka, predominant form will have a net charge of +1. If pH is 3.0, predominant form will have a net charge of 0. If pH is 6.0 predominant form will be the -1 and for a pH of 11.0, predominant form is the -2.

I hope it helps!

a