Biochemistry
6th Edition
ISBN: 9781305577206
Author: Reginald H. Garrett, Charles M. Grisham
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Question
Chapter 19, Problem 9P
Interpretation Introduction
Interpretation:
A suitable chemical mechanism for pyruvate decarboxylase reaction in yeast should be suggested.
Concept Introduction:
Transformation of pyruvate to acetyl-CoA is called pyruvate decarboxylation which is contributed by pyruvate dehydrogenase complex. Acetyl- CoA is used for
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Based on the action of thiamine pyrophosphate in catalysis of the pyruvate dehydrogenase reaction, suggest a suitable mechanism for the fourth step in the pyruvate decarboxylase reaction in yeast:
Compare and contrast Pyruvate Dehydrogenase with a-ketoglutarate dehydrogenaseOutline the mechanisms of both enzymes. Discuss the functions of the coenzymes. List the similarities and the differences between the 2 enzymes. Both are very large membrane bound complexes. What are the advantages of this strategy?How detailed is the enzyme structure known below(It's Pyruvate Dehydrogenase )? What insight(s) does this structural detail give you about the enzyme mechanism.
The glyceraldehyde-3-phosphate-deshydrogenase
glyceraldehyde-3-phosphate in 1,3-bisphosphoglycerate.
catalyses the
catalyses
-CH₂ -CHOH—CHO + Pi + NAD*
the oxidation of
CH₂ CHOH-COQ + H* + NADH
When the enzyme is incubated with iodoacetate, it is observed that glyceraldehyde-3-
phosphate still binds to the modified enzyme, but it is not oxidized. What conclusion
can be drawn from this experiment?
Data: iodoacetate ICH₂COO is an alkylating reagent that react with free sulfhydryl
groups (-SH) to form (-S-CH₂COO).
Chapter 19 Solutions
Biochemistry
Ch. 19 - Radiolabeling with 14C-Glutamate Describe the...Ch. 19 - Prob. 2PCh. 19 - Assessing the Effect of Active-Site...Ch. 19 - Understanding the Mechanism of the -Ketoglutarate...Ch. 19 - Understanding the Action of Fluoroacetate on the...Ch. 19 - Prob. 6PCh. 19 - Prob. 7PCh. 19 - Prob. 8PCh. 19 - Prob. 9PCh. 19 - Prob. 10P
Ch. 19 - Prob. 11PCh. 19 - Prob. 12PCh. 19 - Prob. 13PCh. 19 - Prob. 14PCh. 19 - Prob. 15PCh. 19 - Prob. 16PCh. 19 - Understanding the Oxidation of Glucose and Its...Ch. 19 - Prob. 18PCh. 19 - Prob. 19PCh. 19 - Prob. 20PCh. 19 - Complete oxidation of a 16-carbon fatty acid can...Ch. 19 - Study Figure 19.18 and decide which of the...Ch. 19 - Prob. 23P
Knowledge Booster
Similar questions
- Ethanol as a Source of Metabolic Energy (Integrates with Chapters 19 and 20.) Acetate produced in ethanol metabolism can be transformed into acetyl-COA by the acetyl thiokinase reaction: Acetate+ATP+CoASHacetyleCoA+AMP+PPiAcetyle-CoA then can enter the citric acid cycle and undergo oxidation to 2 CO2by this route, assuming oxidative phosphorylation is part of the process? (Assume all reactions prior to acetyl-CoA entering the citric acid cycle occur outside the mitochondrion). Per carbon atom, which is a better metabolic fuel, ethanol or glucose? That is, how many ATP equivalents per carbon atom are generated by combustion of glucose versus ethanol to CO2?arrow_forwardDistinguishing the Mechanisms of Class I and Class I Aldolases Fructose bisphosphate aldolase in animal muscle is a class 1 aldolase, which forms a Schiff base intermediate between substrate (for example. fructose-1, 6-bisphosphate or dihydroxyacetone phosphate) and a lysine at the active site (see Figure I8.12). The chemical evidence for this intermediate conies from studies with aldolase and the reducing agent sodium borohydride, NaBH4. Incubation of the enzyme with dihydroxyacetone phosphate and NaBH4 inactivates the enzyme. Interestingly, no inactivation is observed if NabH4 is added to the enzyme in the absence of substrate. Write a mechanism that explains these observations and provides evidence for the formation of a Schiff base intermediate in the aldolase reaction.arrow_forwardThe Effect of lodoacetic Acid on the Glyceraldehyde-3-P Dehydrogenase Reaction (Integrates with Chapters 4 and 14.) How might iodoacetic acid affect the glyceraldehydes-3-phosphate dehydrogenase reaction in glycolysis? Justify your answer.arrow_forward
- Understanding the Mechanism of the 3-ketosphinganine Synthase Reaction Write a reasonable mechanism for the 3-ketosphinganine synthase reaction, remembering that it is a pyridoxal phosphate-dependent reaction.arrow_forwardCatalytic mechanism of the Pyruvate Dehydrogenase Complex Match the following coenzymes with the type of reaction or catalytic steps they are associated with during the catalysis of Pyruvate transformation into Acetyl-CoA by the Pyruvate Dehydrogenase Complex: NAD+ V [Choose] formation of a low energy thioester bond decarboxylation TPP oxidation/reduction formation of a high energy thioester bond Coenzyme A [ Choose ] Lipoyl Lysine [ Choose ] FAD [ Choose ]arrow_forwardSketch out the schematic diagram for the enzymatic mechanism of pyruvate dehydrogenase complex Please provide the structure of the functional groups of the substrate and enzyme involved in the reaction at each step (rest of the structure can be indicated as R) Indicate clearly the flow of electrons in the E-1 and E-2 reaction Indicate in short form the cofactor involvedarrow_forward
- Compare and contrast Pyruvate Dehydrogenase with a-ketoglutarate dehydrogenaseOutline the mechanisms of both enzymes. Discuss the functions of the coenzymes. List the similarities and the differences between the 2 enzymes. Both are very large membrane bound complexes. What are the advantages of this strategy?Do a bit or research on the structure one of these enzymes. (include one recent reference) – How detailed is the enzyme structure known? What insight(s) does this structural detail give you about the enzyme mechanism.arrow_forwardArrange the balanced biochemical equations for all the reactions in the payoff phase of glycolysis and the conversion of pyruvate to lactate.arrow_forwardH. OH co co2 но H co, 1-isopropylmalate 2-isopropylmalate Biosynthesis of leucine involves conversion of 1-isopropyimalate to 2-isopropylmalate (see above). This proceeds in four steps under basic enzymic catalysis via an isolable compound produced in step 2. Write a detailed mechanism for this conversion. Then, draw the intermediate compound) produced in step 2. • You do not have to consider stereochemistry. • Draw uninvolved carboxyl groups in the anionic state, and enolates as carbanions. When needed, abbreviate CoenzymeA-S- as CH3S- In your drawing. aalearrow_forward
- Provide a reasonable step-wise mechanism for the reaction below, involving TPP as acoenzyme (can abbreviate the pyrophosphate as R), and invoking any general acids or base fromacetolactate synthase that you might need .arrow_forwardReferring to for E′0 values, calculate ΔG°′ for oxidation of malate by malate dehydrogenase.arrow_forwardPage of 6 ZOOM + name: 3. In the last reaction of the citric acid cycle, malate is dehydrogenated to regenerate the oxaloacetate necessary for the entry of acetyl-CoA into the cycle: L-Malate + NAD+ → oxaloacetate + NADH + H* AG'° = 30.0 kJ/mol (a) Calculate the equilibrium constant for this reaction at 25 °C. (b) Because AG°' assumes a standard pH of 7, the equilibrium constant calculated in (a) corresponds to [oxaloacetate][NADH] Keq [L-malate][NAD*] The measured concentration of L-malate in rat liver mitochondria is about 0.20 mM when [NAD*]/[NADH] is 10. Calculate the concentration of oxaloacetate at pH 7 in these mitochondria. (c) To appreciate the magnitude of the mitochondrial oxaloacetate concentration, calculate the number of oxaloacetate molecules in a single rat liver mitochondrion. Assume the mitochondrion is a sphere of diameter 2.0 microns.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
BiochemistryBiochemistryISBN:9781305577206Author:Reginald H. Garrett, Charles M. GrishamPublisher:Cengage Learning
BiochemistryBiochemistryISBN:9781305961135Author:Mary K. Campbell, Shawn O. Farrell, Owen M. McDougalPublisher:Cengage Learning
Biochemistry
Biochemistry
ISBN:9781305577206
Author:Reginald H. Garrett, Charles M. Grisham
Publisher:Cengage Learning
Biochemistry
Biochemistry
ISBN:9781305961135
Author:Mary K. Campbell, Shawn O. Farrell, Owen M. McDougal
Publisher:Cengage Learning