Which of the following amino acid side chains is often involved in general acid-base catalysis because its pKₐ is near 7?
A)cysteine
B)aspartate
C)histidine
D)lysine

Question

Quizplus · Accepted Answer

Histidine has a pKₐ near 7 (6.0-7.5) and is often involved in general acid-base catalysis in enzymes. Its imidazole side chain can exist in a protonated or deprotonated form, allowing it to donate or accept protons during catalysis.

Which of the Following Amino Acid Side Chains Is Often