The free carboxyl group (-COOH) of a protein acts like:

The free carboxyl group (-COOH) of a protein acts like:

a)a weak base to buffer strong acids

b)a buffer for hydrochloric acid (HCl) in gastric juice

c)a buffer for other carboxyl groups

d)a weak acid to buffer strong bases

e)a buffer for carbonic acid in red blood cells