Concept explainers
Practice Problem 24.8
Glutathione is a tripeptide found in most living cells. Partial acid-catalyzed hydrolysis of glutathione yields two dipeptides, CG and one composed of E and C. When this second dipeptide was treated with DNFB, acid hydrolysis gave N-labeled glutamic acid.
(a) On the basis of this information alone, what structures are possible for glutathione?
(b) Synthetic experiments have shown that the second dipeptide has the following structure:
What is the structure of glutathione?
Want to see the full answer?
Check out a sample textbook solutionChapter 24 Solutions
Organic Chemistry
Additional Science Textbook Solutions
Chemistry & Chemical Reactivity
Basic Chemistry (5th Edition)
Chemistry: The Central Science (13th Edition)
Inorganic Chemistry
Organic Chemistry As a Second Language: Second Semester Topics
General, Organic, and Biological Chemistry (3rd Edition)
- (a) Provide four distinct forms of phenylalanine. (b) Rank the solubility of these forms in water. (c) Explain your ranking.arrow_forwardA tripeptide contains lysine (R= -(CH₂)4NH₂), phenylalanine (R= -CH₂C6H5) and glycine (R= -H). It was found that the tripeptide reacts with 2 moles of DNFB to give compound A. When compound A was treated with SOCI2, glycine was activated. When hydrolyzed, both NH₂ groups of lysine were found to be DNP-labelled. What is the structure of the tripeptide? Select one: H (CH₂)2NH2 CH NH CH H₂N O O H₂N H₂N H₂N C (CH2)4NH2 CH 010 (CH2)4NH2 CH C=O CH,Ph CH NH NH NH CH CH,Ph CH H 010 CH CH,Ph CH (CH2)4NH2 ΝΗ NH NH NH CH,Ph CH H CH COOH H CH COOH COOH COOHarrow_forward(a) What amino acids would be obtained by hydrolysis of the following tripeptide? H,NCHCNHCHCNHCHCOH (CH)2CH H.CоН Н-ССH-СОН (b) How many different tripeptides can be made from gly- cine, serine, and glutamic acid? Give the abbreviation for each of these tripeptides, using the three-letter codes and one-letter codes for the amino acids.arrow_forward
- Some of the most important organic compounds in biochemistry are the α-amino acids, represented by the general formula shown.Write structural formulas for the following α-amino acids.(a) Alanine (R = methyl)(b) Valine (R = isopropyl)(c) Leucine (R = isobutyl)(d) Isoleucine (R = sec-butyl)(e) Serine (R = XCH2, where X is the functional group that characterizes alcohols)(f) Cysteine (R = XCH2, where X is the functional group that characterizes thiols)(g) Aspartic acid (R = XCH2, where X is the functional group that characterizes carboxylic acids)arrow_forwardGive the amino acid sequence of an octapeptide that contains the amino acids Tyr, Ala, Leu (2 equiv), Cys, Gly, Glu, and Val, and forms the following fragments when partially hydrolyzed with HCl: Val–Cys–Gly–Glu, Ala–Leu–Tyr, and Tyr–Leu–Val–Cys.arrow_forwardAnswer the (b) part of the question 6 (a) A decapeptide has the following amino acid composition: Ala2 , Arg, Cys, Glu, Gly, Leu, Lys, Phe, Val Partial hydrolysis yields the following tripeptides: Cys-Glu-Leu + Gly-Arg-Cys + Leu-Ala-Ala+ Lys-Val-Phe + Val-Phe-Gly. Reaction of the decapeptide with 2,4-dinitrofluorobenzene yields 2,4-dinitrophenylysine. From the experimental data, deduce the primary structure of the decapeptide. (b) Suggest a scheme you will follow to synthesize the dipeptide Ala-Glyarrow_forward
- b) Disaccharide E is a reducing sugar. It is hydrolyzed by an α-glycosidase enzyme, which means it contains an α- glycoside link. Treatment of E with Ag2O and excess Mel gives an octamethyl derivative F. Hydrolysis of F in dilute aqueous acid gives the pair of molecules shown below. Write the structures of E and F. (If the stereochemistry at a particular carbon is not determined by the above data, indicate this with a wavy line as shown below.) HO OMe OMe Is is MeO MeO MOH OMe mOH OMe OMearrow_forwardOn complete hydrolysis, a polypeptide gives two alanine, one leucine, one methionine, one phenylalanine, and one valine residue. Partial hydrolysis gives the following fragments: Ala-Phe, Leu-Met, Val-Ala, Phe-Leu. It is known that the first amino acid in the sequence is valine and the last one is methionine. What is the complete sequence of amino acids?arrow_forwardGive the amino acid sequence of a hexapeptide that contains the amino acids Ala, Val, Ser, Ile, Gly, Tyr, and forms the following fragments when partially hydrolyzed with HCl: Gly–Ile–Val, Ala–Ser–Gly, and Tyr–Ala.arrow_forward
- Chemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage LearningOrganic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage LearningChemistry for Today: General, Organic, and Bioche...ChemistryISBN:9781305960060Author:Spencer L. Seager, Michael R. Slabaugh, Maren S. HansenPublisher:Cengage Learning
- Introduction to General, Organic and BiochemistryChemistryISBN:9781285869759Author:Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar TorresPublisher:Cengage Learning