The graphs show a titration curve for the amino acid histidine. Label the fist curve with the major histidine species at each position. One histidine species will not be used. Label the second curve with the p K a values for the histidine functional groups and the isoelectric point ( pI ) of histidine.

Bridget is in science class. her teacher gives her two unknown substances and asks her to determine their relative ph. she places a piece of red litmus paper into both substances. the litmus paper turns purple when she places it into substance i. the litmus paper turns blue when she places it into substance ii. a. substance i is a neutral substance and substance ii is an acid. b. substance i is a neutral substance and substance ii is a base. c. substance i is an acid and substance ii is a base. d. substance i is a base and substance ii is a neutral substance.