The catalytic cofactors required by the pyruvate dehydrogenase complex are to be determined. Concept Introduction: Pyruvate dehydrogenase enzyme complex is required for the linking of glycolysis and TCA. It helps in the conversion of pyruvate into Acetyl CoA. Acetyl CoA then enters into the series of the citric acid cycle.

Question

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Answer 1

Question

Chapter 17, Problem 1P

Interpretation Introduction

Interpretation: The catalytic cofactors required by the pyruvate dehydrogenase complex are to be determined.

Concept Introduction:

Pyruvate dehydrogenase enzyme complex is required for the linking of glycolysis and TCA. It helps in the conversion of pyruvate into Acetyl CoA. Acetyl CoA then enters into the series of the citric acid cycle.

Expert Solution & Answer

Answer to Problem 1P

Correct answer:

The correct answer is the option (a) NAD⁺, lipoic acid, thiamine pyrophosphate.

Explanation of Solution

Explanation/justification for the correct answer:

Option (a) NAD+ , lipoic acid, thiamine pyrophosphate. An irreversible catabolic reaction is catalyzed by the pyruvate dehydrogenase complex. It occurs at the entry point of pyruvate into the TCA cycle. It is a multifunctional enzyme complex. It catalyzes the oxidative decarboxylation of pyruvate to acetyl-CoA, CO2, and NADH.

It uses the NAD⁺, lipoic acid, thiamine pyrophosphate as cofactors. NADH and NAD+ are both forms of a coenzyme nicotinamide adenine dinucleotide. NAD+ get reduced by picking up the electrons lost in the oxidation and forms NADH. Pyruvate dehydrogenase uses the thiamine pyrophosphate or TPP as its prosthetic group. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. Hence, the option (a) is correct.

Conclusion

Explanation for incorrect answer:

Option (b) NAD⁺, biotin, thiamine pyrophosphate. Biotin is involved in some essential metabolic processes such as gluconeogenesis, amino acid catabolism, and fatty acid synthesis. Hence, the option (b) is incorrect.

Option (c) NAD⁺, FAD, lipoic acid. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. These help many organisms to produce energy. Hence, the option (c) is incorrect.

Option (d) FAD, lipoic acid, thiamine pyrophosphate. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. These help many organisms to produce energy. Hence, the option (d) is incorrect.

Thus, an irreversible catabolic reaction is catalyzed by the pyruvate dehydrogenase complex. It occurs at the entry point of pyruvate into the TCA cycle. It uses the NAD⁺, lipoic acid, thiamine pyrophosphate as cofactors. Hence, the option (a) is correct.

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Students have asked these similar questions

. In deciding which form of isocitrate dehydrogenase plays the more important role in the citric acid cycle-the NAD*-dependent or the NADP*-dependent form-what kinds of information would help you?

This is an application question. You are not expected to know anything about the regulation of pyruvate dehydrogenase. Cellular respiration is regulated at many points in the pathway. When ATP levels are high in the cell, NADH molecules accumulate and bind to pyruvate dehydrogenase (the enzyme complex involved in the oxidation of pyruvate) at a site other than the active site to prevent the conversion of pyruvate into acetyl-CoA. This is an example of... O competitive inhibition O allosteric activation O transcriptional cofactors O allosteric inhibition

7. Flow of carbon atoms. What is the fate of the radioac- tive label when each of the following compounds is added to a cell extract containing the enzymes and cofac- tors of the glycolytic pathway, the citric acid cycle, and the pyruvate dehydrogenase complex? (The ¹4C label is printed in red.) (a) (c) H3C H3C O C. O C. COO COO- (b) (d) H3C H₂C O C. O C. (e) Glucose 6-phosphate labeled at C-1. COO™ S-COA

Answer 2

Question

Chapter 17, Problem 1P

Interpretation Introduction

Interpretation: The catalytic cofactors required by the pyruvate dehydrogenase complex are to be determined.

Concept Introduction:

Pyruvate dehydrogenase enzyme complex is required for the linking of glycolysis and TCA. It helps in the conversion of pyruvate into Acetyl CoA. Acetyl CoA then enters into the series of the citric acid cycle.

Expert Solution & Answer

Answer to Problem 1P

Correct answer:

The correct answer is the option (a) NAD⁺, lipoic acid, thiamine pyrophosphate.

Explanation of Solution

Explanation/justification for the correct answer:

Option (a) NAD+ , lipoic acid, thiamine pyrophosphate. An irreversible catabolic reaction is catalyzed by the pyruvate dehydrogenase complex. It occurs at the entry point of pyruvate into the TCA cycle. It is a multifunctional enzyme complex. It catalyzes the oxidative decarboxylation of pyruvate to acetyl-CoA, CO2, and NADH.

It uses the NAD⁺, lipoic acid, thiamine pyrophosphate as cofactors. NADH and NAD+ are both forms of a coenzyme nicotinamide adenine dinucleotide. NAD+ get reduced by picking up the electrons lost in the oxidation and forms NADH. Pyruvate dehydrogenase uses the thiamine pyrophosphate or TPP as its prosthetic group. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. Hence, the option (a) is correct.

Conclusion

Explanation for incorrect answer:

Option (b) NAD⁺, biotin, thiamine pyrophosphate. Biotin is involved in some essential metabolic processes such as gluconeogenesis, amino acid catabolism, and fatty acid synthesis. Hence, the option (b) is incorrect.

Option (c) NAD⁺, FAD, lipoic acid. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. These help many organisms to produce energy. Hence, the option (c) is incorrect.

Option (d) FAD, lipoic acid, thiamine pyrophosphate. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. These help many organisms to produce energy. Hence, the option (d) is incorrect.

Thus, an irreversible catabolic reaction is catalyzed by the pyruvate dehydrogenase complex. It occurs at the entry point of pyruvate into the TCA cycle. It uses the NAD⁺, lipoic acid, thiamine pyrophosphate as cofactors. Hence, the option (a) is correct.

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Answer 3

Question

Chapter 17, Problem 1P

Interpretation Introduction

Interpretation: The catalytic cofactors required by the pyruvate dehydrogenase complex are to be determined.

Concept Introduction:

Pyruvate dehydrogenase enzyme complex is required for the linking of glycolysis and TCA. It helps in the conversion of pyruvate into Acetyl CoA. Acetyl CoA then enters into the series of the citric acid cycle.

Expert Solution & Answer

Answer to Problem 1P

Correct answer:

The correct answer is the option (a) NAD⁺, lipoic acid, thiamine pyrophosphate.

Explanation of Solution

Explanation/justification for the correct answer:

Option (a) NAD+ , lipoic acid, thiamine pyrophosphate. An irreversible catabolic reaction is catalyzed by the pyruvate dehydrogenase complex. It occurs at the entry point of pyruvate into the TCA cycle. It is a multifunctional enzyme complex. It catalyzes the oxidative decarboxylation of pyruvate to acetyl-CoA, CO2, and NADH.

It uses the NAD⁺, lipoic acid, thiamine pyrophosphate as cofactors. NADH and NAD+ are both forms of a coenzyme nicotinamide adenine dinucleotide. NAD+ get reduced by picking up the electrons lost in the oxidation and forms NADH. Pyruvate dehydrogenase uses the thiamine pyrophosphate or TPP as its prosthetic group. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. Hence, the option (a) is correct.

Conclusion

Explanation for incorrect answer:

Option (b) NAD⁺, biotin, thiamine pyrophosphate. Biotin is involved in some essential metabolic processes such as gluconeogenesis, amino acid catabolism, and fatty acid synthesis. Hence, the option (b) is incorrect.

Option (c) NAD⁺, FAD, lipoic acid. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. These help many organisms to produce energy. Hence, the option (c) is incorrect.

Option (d) FAD, lipoic acid, thiamine pyrophosphate. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. These help many organisms to produce energy. Hence, the option (d) is incorrect.

Thus, an irreversible catabolic reaction is catalyzed by the pyruvate dehydrogenase complex. It occurs at the entry point of pyruvate into the TCA cycle. It uses the NAD⁺, lipoic acid, thiamine pyrophosphate as cofactors. Hence, the option (a) is correct.

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Answer 4

Question

Chapter 17, Problem 1P

Interpretation Introduction

Interpretation: The catalytic cofactors required by the pyruvate dehydrogenase complex are to be determined.

Concept Introduction:

Pyruvate dehydrogenase enzyme complex is required for the linking of glycolysis and TCA. It helps in the conversion of pyruvate into Acetyl CoA. Acetyl CoA then enters into the series of the citric acid cycle.

Expert Solution & Answer

Answer to Problem 1P

Correct answer:

The correct answer is the option (a) NAD⁺, lipoic acid, thiamine pyrophosphate.

Explanation of Solution

Explanation/justification for the correct answer:

Option (a) NAD+ , lipoic acid, thiamine pyrophosphate. An irreversible catabolic reaction is catalyzed by the pyruvate dehydrogenase complex. It occurs at the entry point of pyruvate into the TCA cycle. It is a multifunctional enzyme complex. It catalyzes the oxidative decarboxylation of pyruvate to acetyl-CoA, CO2, and NADH.

It uses the NAD⁺, lipoic acid, thiamine pyrophosphate as cofactors. NADH and NAD+ are both forms of a coenzyme nicotinamide adenine dinucleotide. NAD+ get reduced by picking up the electrons lost in the oxidation and forms NADH. Pyruvate dehydrogenase uses the thiamine pyrophosphate or TPP as its prosthetic group. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. Hence, the option (a) is correct.

Conclusion

Explanation for incorrect answer:

Option (b) NAD⁺, biotin, thiamine pyrophosphate. Biotin is involved in some essential metabolic processes such as gluconeogenesis, amino acid catabolism, and fatty acid synthesis. Hence, the option (b) is incorrect.

Option (c) NAD⁺, FAD, lipoic acid. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. These help many organisms to produce energy. Hence, the option (c) is incorrect.

Option (d) FAD, lipoic acid, thiamine pyrophosphate. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. These help many organisms to produce energy. Hence, the option (d) is incorrect.

Thus, an irreversible catabolic reaction is catalyzed by the pyruvate dehydrogenase complex. It occurs at the entry point of pyruvate into the TCA cycle. It uses the NAD⁺, lipoic acid, thiamine pyrophosphate as cofactors. Hence, the option (a) is correct.

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Answer 5

Chapter 17, Problem 1P

Interpretation Introduction

Interpretation: The catalytic cofactors required by the pyruvate dehydrogenase complex are to be determined.

Concept Introduction:

Pyruvate dehydrogenase enzyme complex is required for the linking of glycolysis and TCA. It helps in the conversion of pyruvate into Acetyl CoA. Acetyl CoA then enters into the series of the citric acid cycle.

Expert Solution & Answer

Answer to Problem 1P

Correct answer:

The correct answer is the option (a) NAD⁺, lipoic acid, thiamine pyrophosphate.

Explanation of Solution

Explanation/justification for the correct answer:

Option (a) NAD+ , lipoic acid, thiamine pyrophosphate. An irreversible catabolic reaction is catalyzed by the pyruvate dehydrogenase complex. It occurs at the entry point of pyruvate into the TCA cycle. It is a multifunctional enzyme complex. It catalyzes the oxidative decarboxylation of pyruvate to acetyl-CoA, CO2, and NADH.

It uses the NAD⁺, lipoic acid, thiamine pyrophosphate as cofactors. NADH and NAD+ are both forms of a coenzyme nicotinamide adenine dinucleotide. NAD+ get reduced by picking up the electrons lost in the oxidation and forms NADH. Pyruvate dehydrogenase uses the thiamine pyrophosphate or TPP as its prosthetic group. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. Hence, the option (a) is correct.

Conclusion

Explanation for incorrect answer:

Option (b) NAD⁺, biotin, thiamine pyrophosphate. Biotin is involved in some essential metabolic processes such as gluconeogenesis, amino acid catabolism, and fatty acid synthesis. Hence, the option (b) is incorrect.

Option (c) NAD⁺, FAD, lipoic acid. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. These help many organisms to produce energy. Hence, the option (c) is incorrect.

Option (d) FAD, lipoic acid, thiamine pyrophosphate. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. These help many organisms to produce energy. Hence, the option (d) is incorrect.

Thus, an irreversible catabolic reaction is catalyzed by the pyruvate dehydrogenase complex. It occurs at the entry point of pyruvate into the TCA cycle. It uses the NAD⁺, lipoic acid, thiamine pyrophosphate as cofactors. Hence, the option (a) is correct.

Answer 6

Chapter 17, Problem 1P

Interpretation Introduction

Interpretation: The catalytic cofactors required by the pyruvate dehydrogenase complex are to be determined.

Concept Introduction:

Pyruvate dehydrogenase enzyme complex is required for the linking of glycolysis and TCA. It helps in the conversion of pyruvate into Acetyl CoA. Acetyl CoA then enters into the series of the citric acid cycle.

Expert Solution & Answer

Answer to Problem 1P

Correct answer:

The correct answer is the option (a) NAD⁺, lipoic acid, thiamine pyrophosphate.

Explanation of Solution

Explanation/justification for the correct answer:

Option (a) NAD+ , lipoic acid, thiamine pyrophosphate. An irreversible catabolic reaction is catalyzed by the pyruvate dehydrogenase complex. It occurs at the entry point of pyruvate into the TCA cycle. It is a multifunctional enzyme complex. It catalyzes the oxidative decarboxylation of pyruvate to acetyl-CoA, CO2, and NADH.

It uses the NAD⁺, lipoic acid, thiamine pyrophosphate as cofactors. NADH and NAD+ are both forms of a coenzyme nicotinamide adenine dinucleotide. NAD+ get reduced by picking up the electrons lost in the oxidation and forms NADH. Pyruvate dehydrogenase uses the thiamine pyrophosphate or TPP as its prosthetic group. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. Hence, the option (a) is correct.

Conclusion

Explanation for incorrect answer:

Option (b) NAD⁺, biotin, thiamine pyrophosphate. Biotin is involved in some essential metabolic processes such as gluconeogenesis, amino acid catabolism, and fatty acid synthesis. Hence, the option (b) is incorrect.

Option (c) NAD⁺, FAD, lipoic acid. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. These help many organisms to produce energy. Hence, the option (c) is incorrect.

Option (d) FAD, lipoic acid, thiamine pyrophosphate. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. These help many organisms to produce energy. Hence, the option (d) is incorrect.

Thus, an irreversible catabolic reaction is catalyzed by the pyruvate dehydrogenase complex. It occurs at the entry point of pyruvate into the TCA cycle. It uses the NAD⁺, lipoic acid, thiamine pyrophosphate as cofactors. Hence, the option (a) is correct.

Answer 7

Chapter 17, Problem 1P

Interpretation Introduction

Interpretation: The catalytic cofactors required by the pyruvate dehydrogenase complex are to be determined.

Concept Introduction:

Pyruvate dehydrogenase enzyme complex is required for the linking of glycolysis and TCA. It helps in the conversion of pyruvate into Acetyl CoA. Acetyl CoA then enters into the series of the citric acid cycle.

Answer 8

Expert Solution & Answer

Answer to Problem 1P

Correct answer:

The correct answer is the option (a) NAD⁺, lipoic acid, thiamine pyrophosphate.

Answer 9

Expert Solution & Answer

Answer 10

Expert Solution & Answer

Answer 11

Explanation of Solution

Explanation/justification for the correct answer:

Option (a) NAD+ , lipoic acid, thiamine pyrophosphate. An irreversible catabolic reaction is catalyzed by the pyruvate dehydrogenase complex. It occurs at the entry point of pyruvate into the TCA cycle. It is a multifunctional enzyme complex. It catalyzes the oxidative decarboxylation of pyruvate to acetyl-CoA, CO2, and NADH.

It uses the NAD⁺, lipoic acid, thiamine pyrophosphate as cofactors. NADH and NAD+ are both forms of a coenzyme nicotinamide adenine dinucleotide. NAD+ get reduced by picking up the electrons lost in the oxidation and forms NADH. Pyruvate dehydrogenase uses the thiamine pyrophosphate or TPP as its prosthetic group. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. Hence, the option (a) is correct.

Answer 12

Conclusion

Explanation for incorrect answer:

Option (b) NAD⁺, biotin, thiamine pyrophosphate. Biotin is involved in some essential metabolic processes such as gluconeogenesis, amino acid catabolism, and fatty acid synthesis. Hence, the option (b) is incorrect.

Option (c) NAD⁺, FAD, lipoic acid. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. These help many organisms to produce energy. Hence, the option (c) is incorrect.

Option (d) FAD, lipoic acid, thiamine pyrophosphate. Lipoic acid acts as a cofactor for about five enzyme systems. Two of these enzymes systems are in the Krebs cycle. These help many organisms to produce energy. Hence, the option (d) is incorrect.

Thus, an irreversible catabolic reaction is catalyzed by the pyruvate dehydrogenase complex. It occurs at the entry point of pyruvate into the TCA cycle. It uses the NAD⁺, lipoic acid, thiamine pyrophosphate as cofactors. Hence, the option (a) is correct.

Answer 13

Ch. 17 - Prob. 1P Ch. 17 - Prob. 2P Ch. 17 - Prob. 3P Ch. 17 - Prob. 4P Ch. 17 - Prob. 5P Ch. 17 - Prob. 6P Ch. 17 - Prob. 7P Ch. 17 - Prob. 8P Ch. 17 - Prob. 9P Ch. 17 - Prob. 10P

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