Biochemistry 2288A Lecture Notes - Lecture 2: Acid Dissociation Constant, Stage Name, Ammonia

• School: Western University
• Department: Biochemistry
• Course: Biochemistry 2288A
• Professor: Chris Brandl

Document Summary

Be able to calculate the charge of amino acid groups. An important property of amino acids is their net charge. The net charge changes as the hydrogen ion concentration (ph) changes because of the association of hydrogen ions with the groups. When you lower the ph (increase h+ concentration) the fraction of the molecules that are ionized will decrease. Thus the net charge on the group will decrease. The fraction of the molecules that are ionized increases with decreasing ph. Understand logarithms and the ph scale ph is the symbol for the logarithm of the reciprocal of the hydrogen ion concentration. Be able to calculate ph and pka values. The pka for the amino and carboxl group are xed. Ph>pka = deprotonated pkan is greater than ph so nh3 will be protonated b. Will the protonated or deprotonated form possess a charge? c. what is the ratio of nh3+:nh2. Nh3 will be protonated and will have a positive charge.