Using Figure 1.3 of the Introduction as an example,a) draw all the structures of the tribasic amino acid lysine involved in the equilibrium reactions that would take place during titration against NaOH, starting with the fully protonated form below (draw the R-group in full).HAN+-CH- COOH(CH2)4NH°+b) indicate the numerical pa value of each equilibrium reaction, and which ionizable group is being dissociated in each step.c) indicate the net charge of the amino acid at each step and identify the zwitterion.d) Calculate the pI of this amino acid (show the calculation).e) What would be the predominant ionization states of this amino acid at physiological pH(7.4) and at this pH, what would the ratio of these two states be (show the calculation)? en average the two pra scarboxyl 2.4 and pKa a-amino 9.8) to determine the pI (6.1). Since pH 7.0 is above the pl, there would be nocationic form present, only zwitterionic and anionic forms. The zwitterion would be the conjugate acidwhile the anion would be the conjugate base. The ratio of anion to zwitterion can then be calculatedusing the pKa a-amino and the Henderson-Hasslebalch equation as shown below the figure.HHIINH2-CH-COO™NH3 -CH-COOHNet charge:cation (+1)2.4=pKa a-crboxylCalculation of ratio at pH 7.0:HINH3-CH-COO™zwitterion (0)9.8=pKa a-aminopl= (2.4+9.8)/2 = 6.1Figure 1.3 Dissociation reactions of the dibasic amino acid glycine to illustrate pKa net charge andcalculation of pl. At pH 7.0, only the zwitterionic and anionic forms would be present in solution.pH =pKa + log A/HA7.0 9.8+ log (anion/zwitterion)10-2.8anion/zwitterionanion/zwitterion = 0.00158 or 1/633anion (-1)So, the ratio is 0.00158 anion: 1 zwitterion, or simply 1 anion: 633 zwitterion. From this we can seethat the majority of glycine would be in the zwitterion form at a pH of 7.0.Amino acids with an

The proteins are composed of twenty naturally occurring amino acids. Lysine is a basic amino acid…

Answered: sing Figure 1.3 of the Introduction as…

Biochemistry

9th Edition

ISBN:9781319114671

Author:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Publisher:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Chapter1: Biochemistry: An Evolving Science

Section: Chapter Questions

Problem 1P

See similar textbooks

Related questions

Question

100%

Using Figure 1.3 of the Introduction as an example, a) draw all the structures of the tribasic amino acid lysine involved in the equilibrium reactions that would take place during titration against NaOH, starting with the fully protonated form below (draw the R-group in full). HAN+-CH- COOH (CH2)4 NH°+ b) indicate the numerical pa value of each equilibrium reaction, and which ionizable group is being dissociated in each step. c) indicate the net charge of the amino acid at each step and identify the zwitterion. d) Calculate the pI of this amino acid (show the calculation). e) What would be the predominant ionization states of this amino acid at physiological pH (7.4) and at this pH, what would the ratio of these two states be (show the calculation)?