explain the following answers
8. (3 pts) Consider the structure of histidine, shown below, along with...
8. (3 pts) Consider the structure of histidine, shown below, along with the three pk, values of the three acidic groups. What is the isoelectric point (pl) for histidine? NH2 pka COOH = 1.77 = 6.10 pka, NH3+ = 9.18 pka, ning A) 3.94 C) 5.68 B) 5.48 D) 7.64 histidine OH 9. (3 pts) Which one of the following forms of histidine is the form that would mainly exist near pH = 4? HN NH2 NH3 HN NH3 NH3 A) B) ofery D) at