The PK_a of the Cysteine Side Chain ____ Group Is

Question

The pKaof the cysteine side chain ____ group is 8.32, so it is about 11% deprotonated at pH ____.
A) acid, 3.2
B) amino, 8.5
C) hydroxyl, 10.2
D) sulfhydryl, 7.4
E) none of the above

Accepted Answer

The pKa of the cysteine side chain sulfhydryl group is indeed 8.32, indicating it is the functional group in question. At a pH of 7.4, which is close to physiological pH, the side chain would be approximately 11% deprotonated, following the Henderson-Hasselbalch equation.

The pKa of the cysteine side chain ____ group is 8.32, so it is about 11% deprotonated at pH ____.

The pK_a of the cysteine side chain group is 8.32, so it is about 11% deprotonated at pH .