Amino acids are classified as acidic, basic, or neutral depending upon the relative number of amino and carboxyl groups in their molecule. Basic amino acids contain more amino groups than carboxyl groups. Examples of basic amino acids include Lysine, Arginine, and Histidine. On the other hand, Alanine, Serine, and Tyrosine are neutral amino acids since they contain an equal number of amino and carboxyl groups.