List the amino acids whose R groups are predominantly negatively and positively charged at pH 13.

Abbreviation Name ala cys asp glu phe gly his ile lys leu A C D E F G H H 1 K L M N Q R S T W Y V Alanine Cysteine Aspartic acid Glutamic acid Phenylalanine Glycine Histidine Isoleucine Lysine Leucine Methionine Asparagine Proline Glutamine Arginine Serine Threonine Tryptophan Tyrosine Valine met asn pro gln arg ser thr trp tyr val For the following question, consult a list of the 20 amino acids. a. List the amino acids whose R groups are predominantly negatively charged at pH 13. No partial credit. b. List the amino acids whose R groups are predominantly positively charged at pH 13. No partial credit