Question

For a weak acid such as the side chain ε-amino group of a lysine residue in a protein, if the pKa of that specific residue's ε-amino group is exactly 10.0, in an environment in which the pH = 9.0, what would be the ratio of base to acid?

Answer 1

0.1

Step-by-step explanation:

Using Henderson-Hasselbalch equation

pH = pKa + log ( base / acid )

pH= 9.0 , pKa = 10.0

9.0 = 10 + log ( base / acid )

9 - 10 = log ( base / acid )

10⁻¹ = ( base / acid )

( base / acid ) = 0.1