Section: Biological and Biochemical Foundations of Living Systems

Question 8 of 60

8)
Image for Question

The amino acid histidine has a nitrogen-containing side chain. The pKa for the carboxylic acid group, imidazole side chain, and the primary amine has a value of 1.8, 6.0, and 9.0, respectively. Which of the following structures accurately reflects the predominate form of histidine at a normal physiological pH of 7.4?