EK has a question:
What could be a reasonable explanation for the difference in pKa between the side chains of lysine and arginine?
A. Lysine's side chain has a more stable conjugate base than arginine's side chain
B. Arginine's side chain has a more stable conjugate base than Lysine's side chain
C. Lysine's side chain has a more stable conjugate acid than arginine's side chain
D. Arginine's side chain has a more stable conjugate acid than Lysine's side chain
The answer they go with is A so they're saying the terminal NH2 is more stable than the uncharged terminal guanidium of arginine. I would think the answer should be D because the reason arginine is more basic and able to hold onto the proton is because of its resonance.
What do you guys think?
-rylaboss
What could be a reasonable explanation for the difference in pKa between the side chains of lysine and arginine?
A. Lysine's side chain has a more stable conjugate base than arginine's side chain
B. Arginine's side chain has a more stable conjugate base than Lysine's side chain
C. Lysine's side chain has a more stable conjugate acid than arginine's side chain
D. Arginine's side chain has a more stable conjugate acid than Lysine's side chain
The answer they go with is A so they're saying the terminal NH2 is more stable than the uncharged terminal guanidium of arginine. I would think the answer should be D because the reason arginine is more basic and able to hold onto the proton is because of its resonance.
What do you guys think?
-rylaboss