What is the structure and net charges of Aspartate, Lysine and Alanine at pH 7.5
To determine the structure and net charges of Aspartate, Lysine, and Alanine at pH 7.5, we need to consider the pKa values of their relevant functional groups and the pH of the solution.
1. Aspartate (Asp): At pH 7.5, aspartate is likely to be negatively charged because the pKa of its carboxyl group is around 2.2, which means that it will likely be deprotonated in a solution at pH 7.5. The side chain amino group of aspartate does not have any ionizable groups, so it will not affect the net charge. Therefore, at pH 7.5, aspartate will have a net charge of -1.
2. Lysine (Lys): At pH 7.5, lysine is likely to be positively charged because the pKa of its amino group is around 9.0, which means it will likely be protonated in a solution at pH 7.5. The side chain contains an amino group with a pKa value of approximately 10.5, which means it will also be protonated at pH 7.5. Lysine has a net charge of +1 at pH 7.5.
3. Alanine (Ala): Alanine is a nonpolar amino acid and does not have any ionizable groups in its side chain. Therefore, at pH 7.5, alanine will be electrically neutral with a net charge of 0.
In summary:
- Aspartate (Asp) at pH 7.5 has a net charge of -1.
- Lysine (Lys) at pH 7.5 has a net charge of +1.
- Alanine (Ala) at pH 7.5 has a net charge of 0.