Question 1

An organism that undergoes the glyoxylate cycle can make sugar from fat because:

Accepted Answer

A)  there is a specific isomerase that converts a six carbon fatty acid to glucose 
B)  the unique reactions of the glyoxylate cycle bypass the two decarboyxlation reactions of the citric acid cycle 
C)  glyoxysomes lack succinate dehydrogenase 
D)  none of these 
A)  there is a specific isomerase that converts a six carbon fatty acid to glucose 
B)  the unique reactions of the glyoxylate cycle bypass the two decarboyxlation reactions of the citric acid cycle 
C)  glyoxysomes lack succinate dehydrogenase 
D)  none of these

Question 2

In the conversion of succinyl-CoA to succinate, GTP is produced from GDP in a reaction in which the source of the added phosphate is

Accepted Answer

A)  ATP. 
B)  ADP. 
C)  phosphenolpyruvate. 
D)  inorganic phosphate ion. 
A)  ATP. 
B)  ADP. 
C)  phosphenolpyruvate. 
D)  inorganic phosphate ion.

Question 3

Which enzymes in the citric acid cycle catalyze oxidative decarboxylation reactions?

Accepted Answer

A)  isocitrate dehydrogenase and the α -ketoglutarate dehydrogenase complex 
B)  aconitase and succinate dehydrogenase 
C)  the α -ketoglutarate dehydrogenase complex and succinate thiokinase 
D)  fumarase and succinate dehydrogenase 
A)  isocitrate dehydrogenase and the α -ketoglutarate dehydrogenase complex 
B)  aconitase and succinate dehydrogenase 
C)  the α -ketoglutarate dehydrogenase complex and succinate thiokinase 
D)  fumarase and succinate dehydrogenase

Question 4

Which of the following is true regarding the control of pyruvate dehydrogenase?

Accepted Answer

A)  It is inhibited by ATP 
B)  It is inhibited by NAD+ 
C)  It is activated by acetyl-CoA 
D)  It is inhibited by succinyl-CoA 
E)  none of these are true 
A)  It is inhibited by ATP 
B)  It is inhibited by NAD+ 
C)  It is activated by acetyl-CoA 
D)  It is inhibited by succinyl-CoA 
E)  none of these are true

Question 5

Each of the enzymes of the pyruvate dehydrogenase complex requires a different vitamin.

Accepted Answer

A) True 
 B)False

Question 6

The glyoxylate cycle occurs in

Accepted Answer

A)  plants and animals. 
B)  bacteria and animals. 
C)  plants and bacteria. 
D)  plants, animals, and bacteria. 
A)  plants and animals. 
B)  bacteria and animals. 
C)  plants and bacteria. 
D)  plants, animals, and bacteria.

Question 7

The glyoxylate pathway bypasses part of the citric acid cycle by converting isocitrate to glyoxylate and

Accepted Answer

A)  α -ketoglutarate 
B)  fumarate 
C)  succinyl-CoA 
D)  succinate 
A)  α -ketoglutarate 
B)  fumarate 
C)  succinyl-CoA 
D)  succinate

Question 8

Which of the reactions of the citric acid cycle requires FAD as a coenzyme?

Accepted Answer

A)  the conversion of isocitrate to α -ketoglutarate 
B)  the conversion of citrate to isocitrate 
C)  the conversion of succinate to fumarate 
D)  the conversion of malate to oxaloacetate 
E)  none of these 
A)  the conversion of isocitrate to α -ketoglutarate 
B)  the conversion of citrate to isocitrate 
C)  the conversion of succinate to fumarate 
D)  the conversion of malate to oxaloacetate 
E)  none of these

Question 9

Which of the following enzymes is allosterically inhibited by ATP?

Accepted Answer

A)  pyruvate dehydrogenase complex 
B)  succinyl-CoA synthetase 
C)  succinate dehydrogenase 
D)  fumarase 
A)  pyruvate dehydrogenase complex 
B)  succinyl-CoA synthetase 
C)  succinate dehydrogenase 
D)  fumarase

Question 10

There is a cyclic reaction in which pyruvate becomes oxaloacetate. The oxaloacetate is converted to malate and then back to pyruvate. This cycle is important because:

Accepted Answer

A)  There is no net use or fixation of CO2 in this cycle. 
B)  NADH is converted to NADPH in this cycle. 
C)  There is no net oxidation or reduction in this cycle. 
D)  NADPH is converted to NADH in this cycle. 
E)  This is actually a wasteful pathway with no practical use. 
A)  There is no net use or fixation of CO2 in this cycle. 
B)  NADH is converted to NADPH in this cycle. 
C)  There is no net oxidation or reduction in this cycle. 
D)  NADPH is converted to NADH in this cycle. 
E)  This is actually a wasteful pathway with no practical use.

Question 11

When acetyl-CoA reacts with oxaloacetate to form citrate

Accepted Answer

A)  a new carbon-carbon bond is formed 
B)  an oxidative decarboxylation reaction takes place 
C)  a dehydration reaction takes place 
D)  a rearrangement takes place 
E)  none of these 
A)  a new carbon-carbon bond is formed 
B)  an oxidative decarboxylation reaction takes place 
C)  a dehydration reaction takes place 
D)  a rearrangement takes place 
E)  none of these

Question 12

The only difference between succinate and fumarate is the geometry around their double bonds, one contains a cis double bond and the other contains a trans double bond.

Accepted Answer

A) True 
 B)False

Question 13

A unique feature of the glyoxylate cycle is that it allows the organisms that possess this pathway to

Accepted Answer

A)  produce fats from carbohydrates. 
B)  produce carbohydrates from fats. 
C)  convert acetyl-CoA to pyruvate. 
D)  do all of the above. 
A)  produce fats from carbohydrates. 
B)  produce carbohydrates from fats. 
C)  convert acetyl-CoA to pyruvate. 
D)  do all of the above.

Question 14

Lipoic acid is a required vitamin in the human diet.

Accepted Answer

A) True 
 B)False

Question 15

Which enzyme catalyzes the reaction shown?

Accepted Answer

A)  succinyl-CoA synthetase 
B)  succinate dehydrogenase 
C)  pyruvate dehydrogenase 
D)  α -ketoglutarate dehydrogenase 
A)  succinyl-CoA synthetase 
B)  succinate dehydrogenase 
C)  pyruvate dehydrogenase 
D)  α -ketoglutarate dehydrogenase

Question 16

The immediate electron acceptor for the majority of the oxidative reactions of the citric acid cycle is

Accepted Answer

A)  ATP. 
B)  NAD. 
C)  FAD. 
D)  coenzyme A. 
E)  none of these 
A)  ATP. 
B)  NAD. 
C)  FAD. 
D)  coenzyme A. 
E)  none of these

Question 17

​ Which of the following is true of the inner membrane of a mitochondrion?

Accepted Answer

A)  It is situated between the cytosol and the outer membrane. 
B)  It is situated between the mitochondrial matrix and the cytosol. 
C)  It is permeable to a large number of compounds without a transport protein. 
D)  It is the site where the Embden-Meyerhof-Parnas pathway takes place. 
A)  It is situated between the cytosol and the outer membrane. 
B)  It is situated between the mitochondrial matrix and the cytosol. 
C)  It is permeable to a large number of compounds without a transport protein. 
D)  It is the site where the Embden-Meyerhof-Parnas pathway takes place.

Question 18

Thiamine pyrophosphate carries a ____ carbon unit.

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
A)  1 
B)  2 
C)  3 
D)  4

Question 19

Exhibit 19A The following compounds are all intermediates in the citric acid cycle.   Refer to Exhibit 19A. Which intermediate becomes bonded to Coenzyme A during the cycle?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  5 
A)  1 
B)  2 
C)  3 
D)  4 
E)  5

Question 20

The iron ion, which is part of succinate dehydrogenase, is bonded to heme.

Accepted Answer

A) True 
 B)False

Exam 19: The Citric Acid Cycle

An organism that undergoes the glyoxylate cycle can make sugar from fat because:

In the conversion of succinyl-CoA to succinate, GTP is produced from GDP in a reaction in which the source of the added phosphate is

Which enzymes in the citric acid cycle catalyze oxidative decarboxylation reactions?

Which of the following is true regarding the control of pyruvate dehydrogenase?

Each of the enzymes of the pyruvate dehydrogenase complex requires a different vitamin.

The glyoxylate cycle occurs in

The glyoxylate pathway bypasses part of the citric acid cycle by converting isocitrate to glyoxylate and

Which of the reactions of the citric acid cycle requires FAD as a coenzyme?

Which of the following enzymes is allosterically inhibited by ATP?

There is a cyclic reaction in which pyruvate becomes oxaloacetate. The oxaloacetate is converted to malate and then back to pyruvate. This cycle is important because:

When acetyl-CoA reacts with oxaloacetate to form citrate

The only difference between succinate and fumarate is the geometry around their double bonds, one contains a cis double bond and the other contains a trans double bond.

A unique feature of the glyoxylate cycle is that it allows the organisms that possess this pathway to

Lipoic acid is a required vitamin in the human diet.

Which enzyme catalyzes the reaction shown?

The immediate electron acceptor for the majority of the oxidative reactions of the citric acid cycle is

​ Which of the following is true of the inner membrane of a mitochondrion?

Thiamine pyrophosphate carries a ____ carbon unit.

Exhibit 19A The following compounds are all intermediates in the citric acid cycle. Refer to Exhibit 19A. Which intermediate becomes bonded to Coenzyme A during the cycle?

The iron ion, which is part of succinate dehydrogenase, is bonded to heme.

Biochemistry and the Organization of Cells

Water the Solvent for Biochemical Reactions

Amino Acids and Peptides

The Three Dimensional Structure of Proteins

Protein Purification and Characterization Techniques

The Behavior of Proteins Enzymes

The Behavior of Proteins Enzymes Mechanisms and Control

Lipids and Proteins Are Associated in Biological Membranes

Nucleic Acids How Structure Conveys Information

Biosynthesis of Nucleic Acids Replication

Transcription of the Genetic Code the Biosynthesis of Rna

Protein Synthesis Translation of the Genetic Message

Nucleic Acid Biotechnology Techniques

Viruses Cancer and Immunology

The Importance of Energy Changes and Electron Transfer in Metabolism

Carbohydrates

Glycolysis

Storage Mechanisms and Control in Carbohydrate Metabolism

Electron Transport and Oxidative Phosphorylation

Lipid Metabolism

Photosynthesis

The Metabolism of Nitrogen

Integration of Metabolism Cellular Signaling

Filters

Which of the following is true of the inner membrane of a mitochondrion?