Why is it that although COO- is a conjugate base ; in the R-group of an amino acid, it is considered acidic?

acidic means Proton (H+) donating





basic means proton-accepting.











I am confused. Please help!





Thanks!|||Eg





.acetic acid (CH3COO-H) as an example of a weak acid. It's conjugate base is the acetate anion (CH3COO-). A conjugate base is just what the acid turns into when it gives away its proton (H+). The partial splitting reaction looks like this





(CH3COO-H) 鈫?(CH3COO-) (H+)





A COOH side group is acidic because it donates an H+ producing a conjugate base COO-