Organic Chemistry
8th Edition
ISBN: 9781305580350
Author: William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Question
Chapter 27, Problem 27.38P
Interpretation Introduction
Interpretation:
In the amino acid sequence of human insulin, each Asp, Glu, His, Lys and Arg has to be listed and whether the human insulin contain isoelectric point near acidic amino acid, neutral amino acid or basic amino acid has to be given.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Consider a "tripeptide" with the following features (at pH = 10.8)
• The N-terminal amino acid is leucine
• The middle amino acid is aspartate
• The C-terminal amino acid is lysine
i. What is the 1-letter symbol for each of these amino acids
il. Calculate the net charge of the predominant ionic state of this tripeptide at
pH 10.8. Show work.
If the pH of a solution of Arginine is equal to a half of the 3 pka values of all of its functional groups, what will be the charge on the majority of the Arg molecules in that solution? Please explain. Am i supposedd to add up the three pka values and then divide it in half to find the pH? Thanks
A peptide has the sequence
Glu–His–Trp–Ser–Gly–Leu–Arg–Pro–Gly
The p?a values for the peptide’s side chains, terminal amino groups, and carboxyl groups are provided in the table.
Amino acid
Amino pKa
Carboxyl pKa
Side‑chain pKa
glutamate
9.609.60
2.342.34
4.254.25
histidine
9.179.17
1.821.82
6.006.00
tryptophan
9.399.39
2.382.38
serine
9.159.15
2.212.21
glycine
9.609.60
2.342.34
leucine
9.609.60
2.362.36
arginine
9.049.04
2.172.17
12.4812.48
proline
10.9610.96
1.991.99
Calculate the net charge of the molecule at pH 11 and estimate the isoelectric point (pI)(pI) for this peptide.
Chapter 27 Solutions
Organic Chemistry
Ch. 27.1 - Of the 20 protein-derived amino acids shown in...Ch. 27.2 - Prob. 27.2PCh. 27.2 - Prob. 27.3PCh. 27.3 - Draw a structural formula for Lys-Phe-Ala. Label...Ch. 27.4 - Which of these tripeptides are hydrolyzed by...Ch. 27.4 - Deduce the amino acid sequence of an undecapeptide...Ch. 27.6 - Prob. 27.7PCh. 27 - What amino acid does each abbreviation stand for?...Ch. 27 - The configuration of the chiral center in -amino...Ch. 27 - Assign an R or S configuration to the chiral...
Ch. 27 - Prob. 27.11PCh. 27 - Prob. 27.12PCh. 27 - Draw zwitterion forms of these amino acids. (a)...Ch. 27 - Prob. 27.14PCh. 27 - Why is Arg often referred to as a basic amino...Ch. 27 - Prob. 27.16PCh. 27 - Prob. 27.17PCh. 27 - Prob. 27.18PCh. 27 - Prob. 27.19PCh. 27 - Prob. 27.20PCh. 27 - Both norepinephrine and epinephrine are...Ch. 27 - Prob. 27.22PCh. 27 - Draw a structural formula for the form of each...Ch. 27 - Prob. 27.24PCh. 27 - Write the zwitterion form of alanine and show its...Ch. 27 - Prob. 27.26PCh. 27 - Write the form of aspartic acid most prevalent at...Ch. 27 - Prob. 27.28PCh. 27 - Prob. 27.29PCh. 27 - For lysine and arginine, the isoelectric point,...Ch. 27 - Prob. 27.31PCh. 27 - Account for the fact that the isoelectric point of...Ch. 27 - Prob. 27.33PCh. 27 - Prob. 27.34PCh. 27 - At pH 7.4, the pH of blood plasma, do the majority...Ch. 27 - Prob. 27.36PCh. 27 - Prob. 27.37PCh. 27 - Prob. 27.38PCh. 27 - A chemically modified guanidino group is present...Ch. 27 - Draw a structural formula for the product formed...Ch. 27 - Prob. 27.41PCh. 27 - Prob. 27.42PCh. 27 - A decapeptide has the following amino acid...Ch. 27 - Following is the primary structure of glucagon, a...Ch. 27 - Prob. 27.45PCh. 27 - Draw a structural formula of these tripeptides....Ch. 27 - Estimate the pI of each tripeptide in Problem...Ch. 27 - Glutathione (G-SH), one of the most common...Ch. 27 - Following are a structural formula and a...Ch. 27 - Prob. 27.50PCh. 27 - Prob. 27.51PCh. 27 - Prob. 27.52PCh. 27 - Prob. 27.53PCh. 27 - Prob. 27.54PCh. 27 - Distinguish between intermolecular and...Ch. 27 - Prob. 27.56PCh. 27 - Prob. 27.57P
Knowledge Booster
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
- A professor was preparing a manuscript for publication in which she reported that the pI of the tripeptide Lys-Lys-Lys was 10.6. One of her students pointed out that there must be an error in her calculations because the pKa of the e-amino group of lysine is 10.8 and the pI of the tripeptide has to be greater than any of its individual pKa values. Was the student correct?arrow_forwardAlmost all proteins are composed from a set of about _____ amino acids.a. 4b. 10c. 20d. 50 ______ amino acids are considered essential.a. 5b. 10c. 15d. 20 An amino acid that has an indole group side chain.a. Trpb. Phec. Tyrd. ProWhich of the following is the simplest amino acid?a. Alab. Glyc. Vald. ProWhich of these will not give a blue solution with Ninhydrin testa. Prob. Phec. Alad. CysA neutral molecule with a positive and negative electrical charge.a. Isoelectric pointb. Zwitterionsc. Bufferd. Amphoteric3 amino acids joined together by two peptide bonds.a. Dipeptideb. Tripeptidec. Tetrapeptided. PolypeptideAn amino acid that can form disulfide bondsa. Cysteineb. Methioninec. Cystined. SerineWhich of the following is not a property of amino acidsa. Bufferb. Isoelectric pointc. Zwitterionsd. Insoluble in waterThe protein primary structure is held together bya. Hydrogen bondsb. Disulfide bondsc. Peptide bondsd. Protein bondsarrow_forwardWhy is the amino acid proline not commonly found in alpha-helices or beta-sheets? In what secondary structure might proline be commonly found?arrow_forward
- Hemoglobin A has a pI value of 5.6 whereas the variant hemoglobin M has an aspartate residue in place of the normal valine at position 85 of the alpha chain. What effect will this substitution have on the electrophoretic behavior of the protein at pH 7.0. (explain clearly the reason for your answer)arrow_forwardFinally, you want to make completely certain that you purified the correct protein and not some other protein (like biochemisnotfunase). To confirm the identity of your protein, you run a Western blot. When doing a Western, one typically needs a solution of phosphate-buffered saline, which is comprised of 10 mM phosphate buffer(pH 8.0) and 0.9% (w/v) NaCl. Describe how you would make 500 mL of this solution including the grams of sodium phosphate, monobasic and sodium phosphate, dibasic that you would need. Making the phosphate buffer is a little tricky. Be sure to use the correct ratio of monobasic and dibasic sodium phosphate to get the correct pH. The Henderson- Hasselbalch equation might come in handy here. Finally, the molecular weight of sodium phosphate, monobasic (NaH2PO4) is 119.98 g/mol and the molecular weight of sodium phosphate, dibasic (Na2HPO4) is 141.96 g/mol.arrow_forwardOrnithine is an amino acid that is not used in the synthesis of proteins, but is an important intermediate in several metabloic pathways including the urea cycle and the synthesis of polyamines. It has a perfectly ordinary terminal amino group and terminal carboxyl group like any other amino acid (so use the pKas for those groups given on your amino acids handout), and a side chain with a single ionizable side group with a pKa of 10.3. If ornithine is placed in solution at pH 7.0, it has a net charge of +1. What would the net charge on this amino acid be if the pH of the solution was raised to pH 12.0? Please explain your reasoning.arrow_forward
- The pKa for the side chain amino group in lysine is 10.4. If we were working at physiological pH 7.4, what would be the ratio of the protonated to unprotonated versions of lysine? a. 1000:1 b. 3:1 c. 1:1000 d. 1:3arrow_forwardChemical Connections 20D states that the antigen in the red blood cells of a person with B-type blood is a galactose unit. Show schematically how the antibody of a person with A-type blood would aggregate the red blood cells of a B-type person if such a transfusion were made by mistake.arrow_forwardGlutathione (G-SH), one of the most common tripeptides in animals, plants, and bacteria, is a scavenger of oxidizing agents. In reacting with oxidizing agents, glutathione is converted to G-S-S-G. (a) Name the amino acids in this tripeptide. (b) What is unusual about the peptide bond formed by the N-terminal amino acid? (c) Write a balanced half-reaction for the reaction of two molecules of glutathione to form a disulfide bond. Is glutathione a biological oxidizing agent or a biological reducing agent? (d) Write a balanced equation for reaction of glutathione with molecular oxygen, O2 to form G-S-S-G and H2O. Is molecular oxygen oxidized or reduced in this process?arrow_forward
- Explain why a protein is least soluble in an aqueous medium that has a pH equal to the isoelectric point of the protein.arrow_forwardConsider a peptide: Glu-Glu-His-Trp-Ser-Gly-Leu-Arg-Pro-Gly-His If the pKa values for the sidechains of Glu, His, Arg, and Lys are 4.3, 6.0, 12.5, and 9.7, respectively, determine the net charge at the following pH values. Be sure to write the charge in front (for example, +1/2, +2, and -2). pH 3: __________ pH 8: ___________ pH 11: ___________arrow_forward"A protein has a pI point which can be used to separate proteins using ion exchange. If you have an anion exchange column and access to buffers of any pH, how could you isolate a protein with a pI of 7 from a mixture of proteins which also has proteins with pI points of 3 and 5" Write a few sentences or draw a picture.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Introduction to General, Organic and BiochemistryChemistryISBN:9781285869759Author:Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar TorresPublisher:Cengage Learning
Chemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage Learning
Chemistry for Today: General, Organic, and Bioche...ChemistryISBN:9781305960060Author:Spencer L. Seager, Michael R. Slabaugh, Maren S. HansenPublisher:Cengage Learning
World of Chemistry, 3rd editionChemistryISBN:9781133109655Author:Steven S. Zumdahl, Susan L. Zumdahl, Donald J. DeCostePublisher:Brooks / Cole / Cengage Learning
General, Organic, and Biological ChemistryChemistryISBN:9781285853918Author:H. Stephen StokerPublisher:Cengage Learning
Introduction to General, Organic and Biochemistry
Chemistry
ISBN:9781285869759
Author:Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar Torres
Publisher:Cengage Learning
Chemistry: Principles and Reactions
Chemistry
ISBN:9781305079373
Author:William L. Masterton, Cecile N. Hurley
Publisher:Cengage Learning
Chemistry for Today: General, Organic, and Bioche...
Chemistry
ISBN:9781305960060
Author:Spencer L. Seager, Michael R. Slabaugh, Maren S. Hansen
Publisher:Cengage Learning
World of Chemistry, 3rd edition
Chemistry
ISBN:9781133109655
Author:Steven S. Zumdahl, Susan L. Zumdahl, Donald J. DeCoste
Publisher:Brooks / Cole / Cengage Learning
General, Organic, and Biological Chemistry
Chemistry
ISBN:9781285853918
Author:H. Stephen Stoker
Publisher:Cengage Learning
Biomolecules - Protein - Amino acids; Author: Tutorials Point (India) Ltd.;https://www.youtube.com/watch?v=ySNVPDHJ0ek;License: Standard YouTube License, CC-BY