Question 1

Which of the following vitamins are precursors to coenzymes that are necessary for the formation of acetyl CoA from pyruvate?

Accepted Answer

A)  thiamine, riboflavin, niacin, lipoic acid, and pantothenic acid 
B)  thiamine, riboflavin, niacin, lipoic acid, pantothenic acid, and biotin 
C)  thiamine, riboflavin, niacin, and biotin 
D)  thiamine, riboflavin, and folic acid 
E)  None of the answers is correct. 
A)  thiamine, riboflavin, niacin, lipoic acid, and pantothenic acid 
B)  thiamine, riboflavin, niacin, lipoic acid, pantothenic acid, and biotin 
C)  thiamine, riboflavin, niacin, and biotin 
D)  thiamine, riboflavin, and folic acid 
E)  None of the answers is correct. A

Question 2

Which of the following functions as a "flexible swinging arm" when it transfers the reaction intermediate from one active site to the next?

Accepted Answer

A)  FAD 
B)  NAD+ 
C)  lipoamide 
D)  thiamine pyrophosphate 
E)  coenzyme A 
A)  FAD 
B)  NAD+ 
C)  lipoamide 
D)  thiamine pyrophosphate 
E)  coenzyme A C

Question 3

What type of enzymes are tightly associated with FAD or FMN?

Accepted Answer

A)  transferases 
B)  cytochrome P450 enzymes 
C)  metalloenzymes 
D)  flavoproteins 
E)  None of the answers is correct. 
A)  transferases 
B)  cytochrome P450 enzymes 
C)  metalloenzymes 
D)  flavoproteins 
E)  None of the answers is correct. D

Question 4

Where does the citric acid cycle take place in the cell?

Accepted Answer

A)  cytosol 
B)  mitochondria 
C)  nucleus 
D)  endoplasmic reticulum 
E)  lysosome 
A)  cytosol 
B)  mitochondria 
C)  nucleus 
D)  endoplasmic reticulum 
E)  lysosome

Question 5

In addition to pyruvate dehydrogenase, which of the following enzymes is a key regulatory site in the citric acid cycle?

Accepted Answer

A)  malate dehydrogenase 
B)  $\alpha$-ketoglutarate dehydrogenase 
C)  succinyl CoA synthetase 
D)  succinate dehydrogenase 
E)  None of the answers is correct. 
A)  malate dehydrogenase 
B)  $\alpha$-ketoglutarate dehydrogenase 
C)  succinyl CoA synthetase 
D)  succinate dehydrogenase 
E)  None of the answers is correct.

Question 6

When intermediates of the citric acid cycle are depleted by biosynthetic pathways, _____ reactions are used to replenish the citric acid cycle intermediates.

Accepted Answer

A)  anaplerotic 
B)  amphibolic 
C)  amphoteric 
D)  biosynthetic 
E)  None of the answers is correct. 
A)  anaplerotic 
B)  amphibolic 
C)  amphoteric 
D)  biosynthetic 
E)  None of the answers is correct.

Question 7

Give the reaction in the citric acid cycle by which the energy is conserved in the formation of a phosphoanhydride bond by substrate level phosphorylation. Give the name of the enzyme that catalyzes this reaction and give the structures of the reactants and products of this reaction.

Accepted Answer

The answer of Give the reaction in the citric acid...

Question 8

How does the term "mad as a hatter" realistically reflect the condition?

Accepted Answer

Hatters used mercury in their craft. Fre

Question 9

What molecule initiates the citric acid cycle by reacting with oxaloacetate?

Accepted Answer

A)  pyruvate 
B)  acetyl CoA 
C)  oxaloacetate 
D)  glucose 
E)  None of the answers is correct. 
A)  pyruvate 
B)  acetyl CoA 
C)  oxaloacetate 
D)  glucose 
E)  None of the answers is correct.

Question 10

How does the decarboxylation of $\alpha$-ketoglutarate resemble that of pyruvate decarboxylation?

Accepted Answer

Both are @#LAT-DLM&-ketoacids, which are decarboxy

Question 11

The citric acid cycle is also known as the

Accepted Answer

A)  Krebs cycle. 
B)  Cori cycle. 
C)  tricarboxylic acid cycle. 
D)  acetate cycle. 
E)  Krebs cycle and tricarboxylic acid cycle. 
A)  Krebs cycle. 
B)  Cori cycle. 
C)  tricarboxylic acid cycle. 
D)  acetate cycle. 
E)  Krebs cycle and tricarboxylic acid cycle.

Question 12

What cycle allows for the net synthesis of glucose from acetyl-CoA?

Accepted Answer

A)  Calvin cycle 
B)  glyoxylate cycle 
C)  C4 pathway 
D)  urea cycle 
E)  None of the answers is correct. 
A)  Calvin cycle 
B)  glyoxylate cycle 
C)  C4 pathway 
D)  urea cycle 
E)  None of the answers is correct.

Question 13

Give the net equation of the citric acid cycle.

Accepted Answer

Acetyl-CoA + 3 NAD⁺ +

Question 14

E2 of the pyruvate dehydrogenase complex contains a lipoyl group that is covalently attached to a _______________ residue of the enzyme.

Accepted Answer

The answer of E2 of the pyruvate dehydrogenase complex contains...

Question 15

Which of the following conditions will activate pyruvate dehydrogenase kinase, which catalyzes the phosphorylation and inactivation of E1 in the pyruvate dehydrogenase complex?

Accepted Answer

A)  elevated concentrations of NADH and ATP 
B)  elevated concentrations of NAD+ and ADP 
C)  Ca2+ 
D)  glucagon 
E)  elevated concentrations of coenzyme A 
A)  elevated concentrations of NADH and ATP 
B)  elevated concentrations of NAD+ and ADP 
C)  Ca2+ 
D)  glucagon 
E)  elevated concentrations of coenzyme A

Question 16

Beri-beri is caused by a deficiency of __________________.

Accepted Answer

The answer of Beri-beri is caused by a deficiency of...

Question 17

Which of the following citric acid cycle intermediates is found at the traditional start and finish of the cycle?

Accepted Answer

A)  citrate 
B)  isocitrate 
C)  $\alpha$-ketoglutarate 
D)  succinate 
E)  oxaloacetate 
A)  citrate 
B)  isocitrate 
C)  $\alpha$-ketoglutarate 
D)  succinate 
E)  oxaloacetate

Question 18

Explain why a GTP is energetically equivalent to an ATP in metabolism.

Accepted Answer

The enzyme nucleoside diphosphokinase re

Question 19

Approximately how many ATP or GTP equivalents will be produced from energy molecules produced during one turn of the citric acid cycle?

Accepted Answer

A)  10 
B)  6 
C)  9 
D)  12 
E)  None of the answers is correct. 
A)  10 
B)  6 
C)  9 
D)  12 
E)  None of the answers is correct.

Question 20

What are the steps involved (in order) in the conversion of pyruvate to acetyl-CoA?

Accepted Answer

A)  decarboxylation, oxidation, transfer to CoA 
B)  decarboxylation, transfer to CoA, oxidation 
C)  oxidation, decarboxylation, transfer to CoA 
D)  oxidation, transfer to CoA, decarboxylation 
E)  None of the answers is correct. 
A)  decarboxylation, oxidation, transfer to CoA 
B)  decarboxylation, transfer to CoA, oxidation 
C)  oxidation, decarboxylation, transfer to CoA 
D)  oxidation, transfer to CoA, decarboxylation 
E)  None of the answers is correct.

Exam 17: The Citric Acid Cycle

Which of the following vitamins are precursors to coenzymes that are necessary for the formation of acetyl CoA from pyruvate?

Which of the following functions as a "flexible swinging arm" when it transfers the reaction intermediate from one active site to the next?

What type of enzymes are tightly associated with FAD or FMN?

Where does the citric acid cycle take place in the cell?

In addition to pyruvate dehydrogenase, which of the following enzymes is a key regulatory site in the citric acid cycle?

When intermediates of the citric acid cycle are depleted by biosynthetic pathways, _____ reactions are used to replenish the citric acid cycle intermediates.

Give the reaction in the citric acid cycle by which the energy is conserved in the formation of a phosphoanhydride bond by substrate level phosphorylation. Give the name of the enzyme that catalyzes this reaction and give the structures of the reactants and products of this reaction.

How does the term "mad as a hatter" realistically reflect the condition?

What molecule initiates the citric acid cycle by reacting with oxaloacetate?

How does the decarboxylation of α\alphaα -ketoglutarate resemble that of pyruvate decarboxylation?

The citric acid cycle is also known as the

What cycle allows for the net synthesis of glucose from acetyl-CoA?

Give the net equation of the citric acid cycle.

E2 of the pyruvate dehydrogenase complex contains a lipoyl group that is covalently attached to a _______________ residue of the enzyme.

Which of the following conditions will activate pyruvate dehydrogenase kinase, which catalyzes the phosphorylation and inactivation of E1 in the pyruvate dehydrogenase complex?

Beri-beri is caused by a deficiency of __________________.

Which of the following citric acid cycle intermediates is found at the traditional start and finish of the cycle?

Explain why a GTP is energetically equivalent to an ATP in metabolism.

Approximately how many ATP or GTP equivalents will be produced from energy molecules produced during one turn of the citric acid cycle?

What are the steps involved (in order) in the conversion of pyruvate to acetyl-CoA?

Biochemistry: an Evolving Science

Protein Composition and Structure

Exploring Proteins and Proteomes

DNA, RNA, and the Flow of Genetic Information

Exploring Genes and Genomes

Exploring Evolution and Bioinformatics

Hemoglobin: a Portrait of a Protein in Action

Enzymes: Basic Concepts and Kinetics

Oxidative Phosphorylation

Catalytic Strategies

Regulatory Strategies

Carbohydrates

Lipids and Cell Membranes

Membrane Channels and Pumps

Signal-Transduction Pathways

Metabolism: Basic Concepts and Design

Glycolysis and Gluconeogenesis

The Light Reactions of Photosynthesis

The Calvin Cycle and the Pentose Phosphate Pathway

Glycogen Metabolism

Fatty Acid Metabolism

Protein Turnover and Amino Acid Catabolism

The Biosynthesis of Amino Acids

Nucleotide Biosynthesis

Biosynthesis of Membrane Lipids and Steroids

The Integration of Metabolism

DNA Replication, Repair, and Recombination

Rna Synthesis and Processing

Protein Synthesis

The Control of Gene Expression in Prokaryotes

The Control of Gene Expression in Eukaryotes

Sensory Systems

The Immune System

Molecular Motors

Drug Development

Filters

How does the decarboxylation of $\alpha$ -ketoglutarate resemble that of pyruvate decarboxylation?

Which of the following conditions will activate pyruvate dehydrogenase kinase, which catalyzes the phosphorylation and inactivation of E₁ in the pyruvate dehydrogenase complex?