Question

A protein has an isoelectric point (pI) of 9. Which of the following statements best describes the state of this protein in aqueous solution at pH 7?
A. The side chains of the protein's basic residues will be mostly uncharged
B. The side chains of the protein's acidic residues will be mostly protonated
C. The protein will have no net charge
D. The protein will have a net positive charge
E. The protein will have a net negative charge

Answer 1

Answer:

The  correct option is  D

Explanation:

From the question we are told that

 The pH of the aqueous solution is  $pH = 7$

 The  isoelectric point  is  $pl = 9$

From the data given we see that the  

        $pH$ is  below  $pl$

So the protein will have a net positive charge