Homework Help is Here – Start Your Trial Now!
Science
Chemistry
3. Isoelectric focusing is a separation technique that takes advantage of the differences in isoelectric pH, pl, of polyprotic species like amino acids. A pH gradient is established in a gel matrix using an ampholyte, with the pH of the gel increasing from the anode to the cathode. The amino acids move along the gel – toward the cathode or the anode depending on their initial ionic state – until their charges become equal to zero. This happens when they reach the region in the gel where the pH is equal to their pI values. If the amino acids used in this experiment are the same amino acids specified in question number 1, what are the amino acids R, S, and T? Explain your answer.

3. Isoelectric focusing is a separation technique that takes advantage of the differences in isoelectric pH, pl, of polyprotic species like amino acids. A pH gradient is established in a gel matrix using an ampholyte, with the pH of the gel increasing from the anode to the cathode. The amino acids move along the gel – toward the cathode or the anode depending on their initial ionic state – until their charges become equal to zero. This happens when they reach the region in the gel where the pH is equal to their pI values. If the amino acids used in this experiment are the same amino acids specified in question number 1, what are the amino acids R, S, and T? Explain your answer.

Chemistry: The Molecular Science
Chemistry: The Molecular Science
5th Edition
ISBN:9781285199047
Author:John W. Moore, Conrad L. Stanitski
Publisher:John W. Moore, Conrad L. Stanitski
Chapter14: Acids And Bases
Section14.6: Molecular Structure And Acid Strength
Problem 14.16CE
See similar textbooks
icon
Related questions
Question

ANSWER ONLY NUMBER 3

 

3. Isoelectric focusing is a separation technique that takes advantage of the differences in isoelectric pH, pl, of polyprotic species like amino acids. A pH gradient is established in a gel matrix using an ampholyte, with the pH of the gel increasing from the anode to the cathode. The amino acids move along the gel depending on their initial ionic state - happens when they reach the region in the gel where the pH is equal to their pl values. If the amino acids used in this experiment are the same amino acids specified in question number 1, what are the amino acids R, S, and T? Explain your answer. toward the cathode or the anode until their charges become equal to zero. This Cathode 2 pH T Anode http://oregonstate.edu/instruct/bb450/450material/OutlineMaterials/07 08ProteinCh aracterization/15lsoelectricFocusing.jpeg Isoelectric Focusing
Transcribed Image Text:3. Isoelectric focusing is a separation technique that takes advantage of the differences in isoelectric pH, pl, of polyprotic species like amino acids. A pH gradient is established in a gel matrix using an ampholyte, with the pH of the gel increasing from the anode to the cathode. The amino acids move along the gel depending on their initial ionic state - happens when they reach the region in the gel where the pH is equal to their pl values. If the amino acids used in this experiment are the same amino acids specified in question number 1, what are the amino acids R, S, and T? Explain your answer. toward the cathode or the anode until their charges become equal to zero. This Cathode 2 pH T Anode http://oregonstate.edu/instruct/bb450/450material/OutlineMaterials/07 08ProteinCh aracterization/15lsoelectricFocusing.jpeg Isoelectric Focusing
1. Determine the isoelectric pH (pI) of the amino acids (a) Met, M, (b) Glu, E and (c) Lys, K. Show your solutions clearly and systematically. Draw the structures (showing the states of protonation) of each amino acid before and after consecutive ionizations. Indicate the pH (i.e., pKa) values at which these ionizations occur. Specify the pKa values you used for the calculation of pl. The pKa values of the amino acids' ionizable groups are listed in the table below. Table 23.2 The pKa Values of Amino Acids pKa a-COOH pKa a-NH3* pKa side chain Amino acid Alanine 2.34 9.69 Arginine 2.17 9.04 12.48 Asparagine 2.02 8.84 Aspartic acid 2.09 9.82 3.86 Cysteine 1.92 10.46 8.35 Glutamic acid 2.19 9.67 4.25 Glutamine 2.17 9.13 Glycine 2.34 9.60 Histidine 1.82 9.17 6.04 Isoleucine 2.36 9.68 Leucine 2.36 9.60 Lysine 2.18 8.95 10.79 Methionine 2.28 9.21 Phenylalanine 2.16 9.18 Proline 1.99 10.60 Serine 2.21 9.15 Threonine 2.63 9.10 Tryptophan 2.38 9.39 Tyrosine 2.20 9.11 10.07 Valine 2.32 9.62 https://wps.prenhall.com/wps/media/objects/724/741576/Instructor_ Resources/Chapter_23/Text Images/FG23_TB02.JPG 2. Paper electrophoresis of amino acids can be carried out on a paper that is saturated with a working buffer. The wetted paper is subjected to an electric field, causing the movement of the amino acids down the length of the paper. The negatively charged amino acids migrate to the anode (+ electrode) while the positively charged amino acids migrate to the cathode (– electrode). Shown below is a set-up for paper electrophoresis (left) and an electrophoretic profile of an amino acid mixture (right). If the amino acids used in this experiment are the same amino acids specified in question number 1, what are the amino acids X, Y, and Z? Explain your answer. The buffer used in this experiment is TRIS buffer pH 8.0. cathode anode X Y Z Anode Cathode
Transcribed Image Text:1. Determine the isoelectric pH (pI) of the amino acids (a) Met, M, (b) Glu, E and (c) Lys, K. Show your solutions clearly and systematically. Draw the structures (showing the states of protonation) of each amino acid before and after consecutive ionizations. Indicate the pH (i.e., pKa) values at which these ionizations occur. Specify the pKa values you used for the calculation of pl. The pKa values of the amino acids' ionizable groups are listed in the table below. Table 23.2 The pKa Values of Amino Acids pKa a-COOH pKa a-NH3* pKa side chain Amino acid Alanine 2.34 9.69 Arginine 2.17 9.04 12.48 Asparagine 2.02 8.84 Aspartic acid 2.09 9.82 3.86 Cysteine 1.92 10.46 8.35 Glutamic acid 2.19 9.67 4.25 Glutamine 2.17 9.13 Glycine 2.34 9.60 Histidine 1.82 9.17 6.04 Isoleucine 2.36 9.68 Leucine 2.36 9.60 Lysine 2.18 8.95 10.79 Methionine 2.28 9.21 Phenylalanine 2.16 9.18 Proline 1.99 10.60 Serine 2.21 9.15 Threonine 2.63 9.10 Tryptophan 2.38 9.39 Tyrosine 2.20 9.11 10.07 Valine 2.32 9.62 https://wps.prenhall.com/wps/media/objects/724/741576/Instructor_ Resources/Chapter_23/Text Images/FG23_TB02.JPG 2. Paper electrophoresis of amino acids can be carried out on a paper that is saturated with a working buffer. The wetted paper is subjected to an electric field, causing the movement of the amino acids down the length of the paper. The negatively charged amino acids migrate to the anode (+ electrode) while the positively charged amino acids migrate to the cathode (– electrode). Shown below is a set-up for paper electrophoresis (left) and an electrophoretic profile of an amino acid mixture (right). If the amino acids used in this experiment are the same amino acids specified in question number 1, what are the amino acids X, Y, and Z? Explain your answer. The buffer used in this experiment is TRIS buffer pH 8.0. cathode anode X Y Z Anode Cathode
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps with 3 images

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Knowledge Booster
Green Chemistry
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
Chemistry: The Molecular Science
Chemistry: The Molecular Science
Chemistry
ISBN:
9781285199047
Author:
John W. Moore, Conrad L. Stanitski
Publisher:
Cengage Learning
Introductory Chemistry: A Foundation
Introductory Chemistry: A Foundation
Chemistry
ISBN:
9781337399425
Author:
Steven S. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
SEE MORE TEXTBOOKS