ORGANIC CHEMISTRY
6th Edition
ISBN: 9781260826791
Author: SMITH
Publisher: MCG
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 27, Problem 37P
a. Draw the structure of the tripeptide A–A–A, and label the two ionizable
b. What is the predominant form of A–A–A at
c. The pKa values for the two ionizable functional groups (3.39 and 8.03) differ considerably from the pKa values of alanine (2.35 and 9.87; see Table 29.1). Account for the observed pKa differences.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A. Write the structure of the pentapeptide GLDSC.
B. What is the complete name of this pentapeptide?
Show a tertiary structure of ACGGC after a
disulfide bond forms.
A sample of an unknown peptide was divided into
two aliquots. One aliquot was treated with trypsin;
the other was treated with cyanogen bromide.
Given the following sequences (N-terminal to C-
terminal) of the resulting fragments, deduce the
sequence of the original peptide.
Trypsin treatment
Asn-Thr-Trp-Met-lle-Lys
Gly-Tyr-Met-Gin-Phe
Val-Leu-Gly-Met-Ser-Arg
Cyanogen bromide treatment
Gin-Phe
Val-Leu-Gly-Met
lle-Lys-Gly-Tyr-Met
Ser-Arg-Asn-Thr-Trp-Met
60
61
62
63
The peptide KNYPEH N-terminal amino group has a pKa of 8.6 and the C-terminal carboxylate group has a pKa of 4.5. What is the net charge of this peptide at a pH of 1?
Type your answer...
The peptide KNYPEH N-terminal amino group has a pKa of 8.6 and the C-terminal carboxylate group has a pKa of 4.5. What is the net charge of this peptide at a pH of 7?
Type your answer...
The peptide KNYPEH N-terminal amino group has a pKa of 8.6 and the C-terminal carboxylate group has a pKa of 4.5. What is the net charge of this peptide at a pH of 15?
Type your answer...
The peptide KNYPEH N-terminal amino group has a pKa of 8.6 and the C-terminal carboxylate group has a pKa of 4.5. What is the isoelectric point of this peptide?
Type your answer...
DU
Calculate the isoelectric point for each amino acid.a. cysteine: pKa (COOH) = 2.05; pKa (a-NH3+) = 10.25b. methionine: pKa (COOH) = 2.28; pKa (a-NH3+) = 9.21
Chapter 27 Solutions
ORGANIC CHEMISTRY
Ch. 27.1 - Prob. 1PCh. 27.1 - Problem 29.2
What form exists at the isoelectric...Ch. 27.1 - Problem 29.3
Explain why the of the group of an...Ch. 27.1 - Prob. 4PCh. 27.2 - Problem 29.5
What -halo carbonyl compound is...Ch. 27.2 - Problem 29.6
The enolate derived from diethyl...Ch. 27.2 - Problem 29.7
What amino acid is formed when is...Ch. 27.2 - Problem 29.8
What aldehyde is needed to synthesize...Ch. 27.2 - Problem 29.9
Draw the products of each...Ch. 27.3 - Prob. 10P
Ch. 27.3 - Prob. 11PCh. 27.3 - Prob. 12PCh. 27.4 - Problem 29.13
What alkene is needed to synthesize...Ch. 27.5 - Problem 29.14
Draw the structure of each peptide....Ch. 27.5 - Problem 29.15
Name each peptide using both the...Ch. 27 - Draw the product formed when the following amino...Ch. 27 - With reference to the following peptide: a...Ch. 27 - Prob. 31PCh. 27 - Histidine is classified as a basic amino acid...Ch. 27 - Tryptophan is not classified as a basic amino acid...Ch. 27 - What is the structure of each amino acid at its...Ch. 27 - What is the predominant form of each of the...Ch. 27 - 29.37 What is the predominant form of each of the...Ch. 27 - a. Draw the structure of the tripeptide A–A–A, and...Ch. 27 - 29.39 Draw the organic products formed in each...Ch. 27 - 29.40 What alkyl halide is needed to synthesize...Ch. 27 - Prob. 50PCh. 27 - Draw the structure for each peptide: (a) Phe–Ala;...Ch. 27 - 29.52 For the tetrapeptide Asp–Arg–Val–Tyr:
a....Ch. 27 - Prob. 53PCh. 27 - Prob. 54PCh. 27 - 29.55 Draw the amino acids and peptide fragments...Ch. 27 - Prob. 56PCh. 27 - Prob. 57PCh. 27 - Prob. 58PCh. 27 - 29.59 An octapeptide contains the following amino...Ch. 27 - 29.60 Draw the organic products formed in each...Ch. 27 - 29.65 Draw the mechanism for the reaction that...Ch. 27 - 29.66 Which of the following amino acids are...Ch. 27 - 29.67 After the peptide chain of collagen has been...Ch. 27 - Prob. 68PCh. 27 - Prob. 69PCh. 27 - 29.70 The anti-obesity drug orlistat works by...Ch. 27 - Prob. 71P
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
- Explain why the pKa of the - NH3+ group of an a-amino acid is lower than the pKa of the ammonium ion derived from a 1° amine (RNH3+). For example the pKa of the - NH3+ group of alanine is 9.87 but the pKa of CH3NH3+ is 10.63.arrow_forward10. Which side chain would most likely be found in the interior of a protein, away from the aqueous environment? a. -CH2OH b. -CH2SH с. -СH-CООН d. -CH2CONH2 e.arrow_forwardExplain the difference in the pKa values of the carboxyl groups of alanine, serine, and cysteine.arrow_forward
- Which of the following clarifications is false? Select one: to. fibroin contains AA with sparse side chains b. disulfide bridges play an important role in maintaining alpha keratin structures. C. fibroin is a protein in which polypeptide chains are organized into beta folded sheets d. Gly residues are abundant in collagen е. collagen is a protein in which polypeptides are in the alpha helix conformationarrow_forward3. Draw the tripeptide Alanine-Cysteine-Serine (R1 = CH3, R2 = CH2SH, R3 = CH2OH) under the following pH conditions and list the net charge on the protein. A. pH= 1 Net charge? B. pH=7 Net charge? C. pH=12 Net charge?arrow_forwardThe 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_forward
- Select the correct representation of this aminoacid in aqueous solution at the stated pH values. pKa (a-CO₂H) = 2.20 pK₂ (α-NH₂) = 9.11 pKa (side chain OH) = 10.07 pl = 5.63 HO Lont out on on OH OH NH₂ NH₂ NH₁ HO NH₂ B D at pH 1 HO NH₂ of of an OH NH₂ NH₂ NH3 O E F G at pH 9.59 at pH 13. at pH 5.63 (the isoelectric point) HO OH HO [Choose ] [Choose ] [Choose ] [Choose ] an NH3 H OHarrow_forwardBased on the given figure,a. what is the possible identity of the amino acid?b. what is the isoelectric point of AAc. what is the pKa corresponding to the dissociation of alpha carboxylic groupd. where is the region or point where AA is predominantly present as a (-2) charged speciese. where is the effective buffering range for the amino acid on the acidic regionarrow_forwardCalculate the isoelectric point for each amino acid. a. cysteine: pKa (COOH) = 2.05; pKa (α-NH3+) = 10.25 b. methionine: pKa (COOH) = 2.28; pKa (α-NH3+) = 9.21arrow_forward
- 1. a) Classify the amino acids according to the nature of their side chains (R groups), stating which are polar, non-polar, acidic and basic. Draw the structure of the amino acid glutamic acid in neutral solution at pH7.0. b) What is meant by the term isoelectric point of an amino acid? Discuss how is it related to the pKa values of an amino acid? c) What practical technique would you use to separate a mixture of the amino acids arginine, valine and glutamic acid? State briefly how it works. d) Describe in detail the two analytical methods that can be used to separate a complex mixture of proteins, yielding individual proteins with different amino acid sequences. Many thanks.arrow_forward8. The following proteins represent a wide range of molecular weights and isoelectric points. Mr is the molecular weight of a single protein chain. • Protein 1: Mr 68,544; pl 6.11 (monomer) • Protein 2: Mr 29,041; pl 5.32 (dimer) • Protein 3: Mr 15,805; pl 5.7 (dimer) • Protein 4: Mr 12,165; pl 4.74 a. Which protein is the most acidic? Explain your answer. b. Which protein will migrate the slowest in an SDS-PAGE? Explain your answer. c. In what order will these proteins elute from a cation exchanger at pH 8? Explain your answer. d. In what order will these proteins salt out from a pH 7 solution by the dropwise addition of saturated ammonium sulfate? Explain your answer. 5 83°F Cloudyarrow_forward1. Draw the tetrapeptide DASK and estimate the pl. What is the approximate net charge on the peptide at pH 2, pH 7, and pH 12?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Biomolecules - Protein - Amino acids; Author: Tutorials Point (India) Ltd.;https://www.youtube.com/watch?v=ySNVPDHJ0ek;License: Standard YouTube License, CC-BY