The amino acid glycine has an carboxyl group, amino group (NH3), and 2 hydrogens attached to the alpha carbon. If an additional adjacent carboxyl group were added, would the pKa of the other carboxyl group increase or decrease?
I was thinking it would decrease since I know that dicarboxylic acids tend to generally be more acidic than just 1 carboxylic acid by itself. However, I'm not sure how the presence of the NH3 group affects this. I know it is also electron withdrawing, but oxygen beats out nitrogen in terms of electronegativity, so I don't know if that makes a difference here.