Calculating the pl for an amino acid without an ionizable side chain is straightforward. Simply the average of the pKa values for the amine and the carboxylic acid. For example, for glycine, the calculation is as follows: pl = рKа-соон + рKа-NH₂ 2 2.34 + 9.60 2 = 5.97 For amino acids with ionizable side chains, the pl is calculated by averaging the pKa values of either the two acidic groups or the two basic groups. For example, for glutamic acid, which has two acidic carboxylic acid groups, the calculation is as follows: Calculate the PI for the amino acid lysine (Lys).

Calculating the pl for an amino acid without an ionizable side chain is straightforward. Simply the average of the pKa values for the amine and the carboxylic acid. For example, for glycine, the calculation is as follows: pl = рKа-соон + рKа-NH₂ 2 2.34 + 9.60 2 = 5.97 For amino acids with ionizable side chains, the pl is calculated by averaging the pKa values of either the two acidic groups or the two basic groups. For example, for glutamic acid, which has two acidic carboxylic acid groups, the calculation is as follows: Calculate the PI for the amino acid lysine (Lys).

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

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Spectroanalytical Methods

Spectroanalytical methods measure the wavelength and intensity of radiations that are either emitted or absorbed by a molecular or atomic species. These methods are useful for evaluating the electronic or atomic arrangement of the molecules of a given analyte.

Question

Calculating the pl for an amino acid without an ionizable side chain is straightforward.
Simply the average of the pKa values for the amine and the carboxylic acid. For
example, for glycine, the calculation is as follows:
pl =
pKa-cooH + pKa-NH,
2
2.34 + 9.60
2
= 5.97
For amino acids with ionizable side chains, the pl is calculated by averaging the pKa
values of either the two acidic groups or the two basic groups. For example, for glutamic
acid, which has two acidic carboxylic acid groups, the calculation is as follows:
Calculate the PI for the amino acid lysine (Lys).
Calculating the pl for peptides and proteins is slightly more complicated but follows the
same general concept.

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The isoelectric point (pl) can best be calculated by: Averaging the sums of all pkas. Averaging the sum of the two pKas closest to physiological pH. Averaging the two pKas "sandwiching" the zwitterionic form. Averaging the two pKas of the alpha-amino and alpha-carboxy groups.
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Which of the following amino acids is most likely to have a positively-charged side group under normal physiological pH conditions? O a. Lysine O b. Alanine O c. Leucine O d. Glycine O e. Aspartic acid Next page Previous page Time left 1:33:55 Quiz navigation 271 PM 今 D 572 2022 DELL Delete PgUp PgDn F12 PrtScr Insert F9 F10 F11 F7 F8 F5 F6 F2 F3 F4 Esc F1 Backspace & % %3D @ # 8 6 7 3 1 Y Enter J K A s D F ck St