Question

The side chain of histidine has a pKa of about 6. What percent of histidine side chains would be deprotonated at pH 7.5

Answer 1

The percent of histidine side chains would be deprotonated at pH 7.5  is 5.77 %.

What is pKa?

The term pKa refers to the negative logarithm of the acid dissociation constant (Ka). The pH is the negative logarithm of the hydrogen ion concentration.

Hence;

Ka = Antilog (-6) =$1 * 10^-6$

[H^+] = Antilog (-7.5) = $3 * 10^-8 M$

We now have to use the formula;

α = $\sqrt{} \frac{Ka}{[H^+] }$

α = $\sqrt{} \frac{ 1 *10^-6}{3 *10^-8 }$

α = 5.77 %

Hence, the percent of histidine side chains would be deprotonated at pH 7.5  is 5.77 %.

Learn more about percent dissociation: brainly.com/question/12273293