Organic Chemistry (8th Edition)
8th Edition
ISBN: 9780134042282
Author: Paula Yurkanis Bruice
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 23.5, Problem 15P
Explain why the ability of PLP to catalyze an amino acid transformation is greatly reduced if a PLP-requiring enzymatic reaction is carried out at a pH at which the pyridine nitrogen is not protonated.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
The hydrolysis of an ester can be sped up by both acidic and basic conditions. Aminolysis of an ester can be sped up by acidic conditions, but not by basic conditions. Explain why.
Ethyleneimine reacts with cysteine side chains in proteins to form S - aminoethyl derivatives. The peptide bonds on the carboxyl side of these modified cysteine residues are susceptible to hydrolysis by trypsin . Why?
Reaction of the a-carboxyl group of an amino acid or peptide with phenylisothiocyanate allows for the determination of the amino acid residue in the N-
terminus of an unknown peptide
O True
O False
Chapter 23 Solutions
Organic Chemistry (8th Edition)
Ch. 23.1 - Prob. 2PCh. 23.1 - Prob. 3PCh. 23.2 - How many conjugated double bonds are there in a....Ch. 23.2 - Instead of adding to the 4a position and...Ch. 23.2 - Prob. 7PCh. 23.3 - Prob. 8PCh. 23.3 - Acetolactate synthase is another TPP-requiring...Ch. 23.3 - Acetolactate synthase transfers the acyl group of...Ch. 23.3 - Prob. 12PCh. 23.5 - Which compound is more easily decarboxylated?
Ch. 23.5 - Prob. 14PCh. 23.5 - Explain why the ability of PLP to catalyze an...Ch. 23.5 - Explain why the ability of PLP to catalyze an...Ch. 23.5 - The enzyme that catalyzes the C C bond cleavage...Ch. 23.5 - Propose a mechanism for the ,-elimination reaction...Ch. 23.6 - Ethanolamine ammonia lyase, a coenzyme...Ch. 23.6 - Prob. 20PCh. 23.7 - How do the structure of tetrahydrofolate and...Ch. 23.7 - What is the source of the methyl group in...Ch. 23.8 - Thiols such as ethanethiol and propanethiol can be...Ch. 23 - How does the metal ion in carboxypeptidase A...Ch. 23 - Prob. 24PCh. 23 - Prob. 25PCh. 23 - For each of the following reactions, name both the...Ch. 23 - Prob. 27PCh. 23 - When transaminated, the three branched-chain amino...Ch. 23 - What acyl groups have we seen transferred by...Ch. 23 - Propose a mechanism for the following reaction:Ch. 23 - Draw the products of the following reaction, where...Ch. 23 - When UMP is dissolved in T2O, exchange of T for H...Ch. 23 - Dehydratase is a PLP-requiring enzyme that...Ch. 23 - In addition to the reaction mentioned in Section...Ch. 23 - PLP can catalyze both ,-elimination reactions...Ch. 23 - The glycine cleavage system is a group of four...Ch. 23 - Prob. 37PCh. 23 - FADH2 reduces , -unsaturated thioesters to...
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 rate of aminolysis of an ester cannot be increased by H+, HO-, or RO-.arrow_forwardα-Amino acids can be prepared by treating an aldehyde with ammonia/trace acid, followed by hydrogen cyanide, followed by acid-catalyzed hydrolysis. What amino acid is formed when the aldehyde that is used is 3-methylbutanal?arrow_forwardAn enzyme catalyzes the hydrolysis of an ester with a certain activity, but this activity is lost in a 3 M urea solution. What is the most likely explanation for the loss of activity? (A) Urea binds to the active site of the enzyme competitively with the substrate. (B) Urea causes the cleavage of the peptide bonds in the enzyme. (C) Urea causes the enzyme to denature and lose its specific three-dimensional shape. (D) Urea reacts with disulfide bonds in the enzyme.arrow_forward
- Draw the structure of the predominant form of a mixture of alanine, lysine, and aspartic acid at (i) pH 6; (ii) pH 11; (iii) pH 2.arrow_forwardA chemically modified guanidino group is present in cimetidine (Tagamet), a widely prescribed drug for the control of gastric acidity and peptic ulcers. Cimetidine reduces gastric acid secretion by inhibiting the interaction of histamine with gastric H2 receptors. In the development of this drug, a cyano group was added to the substituted guanidino group to alter its basicity. Do you expect this modified guanidino group to be more basic or less basic than the guanidino group of arginine? Explain.arrow_forward22-97 Gelatin is derived from collagen by denaturation. Is a gelatin dessert likely to be a good source of dietary protein?arrow_forward
- Both norepinephrine and epinephrine are synthesized from the same protein-derived amino acid. From which amino acid are they synthesized? What types of reactions are involved in their biosynthesis?arrow_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_forward-Amino acids can be prepared by the Strecker synthesis, a two-step process in which an aldehyde is treated with ammonium cyanide followed by hydrolysis of the amino nitrile intermediate with aqueous acid. Propose a mechanism for the reaction.arrow_forward
- The addition of a nucleophilic group like a thiol (-SH), or an unprotonated amino group (-NH₂) to an a,ß-unsaturated ketone is important for understanding how NAPQI reacts with glutathione, N-acetylcysteine, or protein amino acid side chains containing -SH or -NH2 groups. In this problem we will add mercaptoethanol to p-benzoquinone. p-Benzoquinone will be a simple model of NAPQI. +H H a single uncharged addition product This reaction will proceed in steps. First the H-S-R will add to the unsaturated ketone to give a charged addition product. Next, a simple proton transfer will form an uncharged adduct in which the 6-membered ring contains one carbonyl and a second enolic hydroxyl. The keto form next will tautomerize to its more stable enol form, and in doing so the 6-membered ring becomes aromatic with 6-π electrons. See page 14 of the lecture notes for Lecture 9 How ADME affects preclinical Drug Design February 24, 2023, where I have shown the mechanism for this addition and give the…arrow_forwardWhich of the following substituent is an ortho/para-directing activator and an ortho/para-directing deactivator? a amino group b halogen group c nitro group d carboxyl grouparrow_forwardA variation of the acetamidomalonate synthesis can be used to synthesize serine. The process involves the following steps: Ethoxide ion deprotonates diethyl acetamidomalonate, forming enolate anion 1; Enolate anion 1 makes a nucleophilic attack on formaldehyde, forming tetrahedral intermediate 2; Protonation of the oxyanion forms alcohol 3; Acid hydrolysis yields dicarboxyamino alcohol 4; Decarboxylation leads to the final amino acid. Write out the mechanism on a separate sheet of paper, and then draw the structure of tetrahedral intermediate 2. You do not have to consider stereochemistry. You do not have to explicitly draw H atoms. Do not include lone pairs in your answer. They will not be considered in the grading. Draw carboxyl and amino groups in their uncharged forms.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
Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning
Chemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher: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
Organic Chemistry
Chemistry
ISBN:9781305580350
Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote
Publisher:Cengage Learning
Chemistry: Principles and Reactions
Chemistry
ISBN:9781305079373
Author:William L. Masterton, Cecile N. Hurley
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