Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 23: Q10P (page 1076)

Acetolactatesynthasetransfers the acyl group of pyruvate to \(\alpha \)-ketobutyrate. This is the first step in the biosynthesis of the amino acid isoleucine. Propose a mechanism for this reaction.

Short Answer

Expert verified

In question it is mentioned that acetolactate synthase enzyme needs TTP for transferring acyl group from pyruvate to alpha-ketobutyrate to form alpha-aceto-alpha-hydroxybutyrate and remove carbon-dioxide.

Step by step solution

01

Acetolactate synthase role

In question it is mentioned that acetolactate synthase enzyme needs TTP for transferring acyl group from pyruvate to alpha-ketobutyrate to form alpha-aceto-alpha-hydroxybutyrate and remove carbon-dioxide.

02

Mechanism of action

The mechanism for the reaction is as follows:

  • First step is proton removal from TPP forming TPP-ylide.
  • TPP-ylide attaches to the carbonyl carbon of pyruvate.
  • The tetrahedral intermediate formed here easily undergoes decarboxylation by reaction giving TPP-enamine.
  • Addition of alpha-ketobutyrate occurs on the TPP-enamine carbon and afterward elimination from the tetrahedral intermediate occur forming alpha-aceto-alpha-hydroxybutyrate and regenerates the TPP-ylide.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Question:When UMP is dissolved in T2O, exchange of T for H occurs at the 5-position. Propose a mechanism for this exchange.

Question:Thiols such as ethanethiol and propanethiol can be used to reduce vitamin K epoxide to vitamin KH2, but they react much more slowly than dihydrolipoate. Explain why this is so.

Question: Answer the following:

a. What coenzyme transfers an acyl group from one substrate to another?

b. What is the function of FAD in the pyruvate dehydrogenase complex?

c. What is the function of NAD+ in the pyruvate dehydrogenase complex?

d. What reaction necessary for proper blood clotting is catalyzed by vitamin KH2?

e. What coenzymes are used for decarboxylation reactions?

f. What kinds of substrates do the decarboxylating coenzymes work on?

g. What coenzymes are used for carboxylation reactions?

h.What kinds of substrates do the carboxylating coenzymes work on?

Question: What is the source of the methyl group in thymidine?

a. What acyl group does pyruvate decarboxylase transfer to a proton?

b. What acyl group does the pyruvate dehydrogenase complex transfer to coenzyme A?

c. What acyl group does transketolase transfer to ribose-5-P?
See all solutions

Recommended explanations on Chemistry Textbooks

Nuclear Chemistry

Read Explanation

Physical Chemistry

Read Explanation

Kinetics

Read Explanation

Chemistry Branches

Read Explanation

Making Measurements

Read Explanation

Chemical Reactions

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free