Question 1

The a-ketoglutarate and succinate dehydrogenase complexes are the only oligomeric enzymes used in the citric acid cycle.

Accepted Answer

A) True 
 B)False

Question 2

ATP is consumed by the pyruvate dehydrogenase complex during the synthesis of acetyl CoA.

Accepted Answer

A) True 
 B)False

Question 3

In citrus fruits,the levels of citric acid are related to its ability to conduct a citric acid cycle of reactions and not to its ability to act as a preservative or a reservoir of carbon.

Accepted Answer

A) True 
 B)False

Question 4

The succinate dehydrogenase reaction is unusual for a dehydrogenase because it uses ________ as an electron acceptor (oxidizing agent)that is regenerated by ubiquinone.

Accepted Answer

A) ATP 
B) NADP 
C) Malonate 
D) FAD 
A) ATP 
B) NADP 
C) Malonate 
D) FAD

Question 5

The mechanism of pyruvate dehydrogenase complex is an example of channeling.

Accepted Answer

A) True 
 B)False

Question 6

Citrate is chemically symmetric but is a prochiral molecule because the two acetyl groups are specifically oriented by the enzyme aconitase.

Accepted Answer

A) True 
 B)False

Question 7

The succinate dehydrogenase complex catalyzes

Accepted Answer

A) the formation of a single hydrogen bond in the oxidation of succinate to fumarate. 
B) the formation of a double bond in the oxidation of succinate to fumarate. 
C) Both A and B. 
D) None of the above. 
A) the formation of a single hydrogen bond in the oxidation of succinate to fumarate. 
B) the formation of a double bond in the oxidation of succinate to fumarate. 
C) Both A and B. 
D) None of the above.

Question 8

Which enzyme is the same in both the pyruvate dehydrogenase and α-ketoglutarate complexes?

Accepted Answer

A) Dihydrolipoamide dehydrogenase. 
B) Aconitase. 
C) Pyruvate decarboxylase. 
D) The two complexes have no components that are similar. 
A) Dihydrolipoamide dehydrogenase. 
B) Aconitase. 
C) Pyruvate decarboxylase. 
D) The two complexes have no components that are similar.

Question 9

Please match the following reactions to their respective energy yielding products.
Please note that a product may be used once,more than once,or not at all as an answer.
-Isocitrate dehydrogenase

Accepted Answer

A) NADH 
B) QH² 
C) GTP or ATP 
A) NADH 
B) QH² 
C) GTP or ATP

Question 10

The pyruvate dehydrogenase complex is located inside mitochondria .Pyruvate is formed by glycolysis in the cytoplasm.Pyruvate is brought into the mitochondrion by

Accepted Answer

A) diffusion. 
B) TCA transporter. 
C) PEP transporter. 
D) Pyruvate transporter. 
A) diffusion. 
B) TCA transporter. 
C) PEP transporter. 
D) Pyruvate transporter.

Question 11

Which product of the citric acid cycle produces the most ATP equivalents?

Accepted Answer

A) NADH. 
B) QH2. 
C) GTP. 
D) CO2. 
A) NADH. 
B) QH2. 
C) GTP. 
D) CO2.

Question 12

Please match the following reactions to their respective energy yielding products.
Please note that a product may be used once,more than once,or not at all as an answer.
-Malate dehydrogenase

Accepted Answer

A) NADH 
B) QH² 
C) GTP or ATP 
A) NADH 
B) QH² 
C) GTP or ATP

Question 13

The activity of dihydrolipoamide acetyltransferase (E2)is inhibited when the concentration of acetyl CoA is decreased.

Accepted Answer

A) True 
 B)False

Question 14

About how many total ATP equivalents are generated by the complete oxidation of one molecule of acetyl CoA?

Accepted Answer

A) 1.5 
B) 2.5 
C) 3 
D) 10 
E) 30 
A) 1.5 
B) 2.5 
C) 3 
D) 10 
E) 30

Question 15

All members of the aconitase family of proteins contain an iron sulfur cluster.

Accepted Answer

A) True 
 B)False

Question 16

Which process is not implicated in the evolution of the citric acid cycle pathway?

Accepted Answer

A) Gene duplication. 
B) Palindromic inversion. 
C) Pathway extension. 
D) Pathway reversal. 
E) Enzyme theft. 
A) Gene duplication. 
B) Palindromic inversion. 
C) Pathway extension. 
D) Pathway reversal. 
E) Enzyme theft.

Question 17

The citric acid cycle is an anaerobic pathway that occurs in the mitochondria of eukaryotes.

Accepted Answer

A) True 
 B)False

Question 18

Which of the following enzymatic reactions are examples of substrate level phosphorylation?

Accepted Answer

A) Succinyl Co-A synthetase. 
B) Pyruvate kinase. 
C) Phosphoglycerate kinase. 
D) All of the above. 
A) Succinyl Co-A synthetase. 
B) Pyruvate kinase. 
C) Phosphoglycerate kinase. 
D) All of the above.

Question 19

After passing through pyruvate dehydrogenase and the citric acid cycle,one mole of pyruvate will result in the formation of ________ moles of carbon dioxide and ________ mole(s)of ATP (or GTP).

Accepted Answer

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

Question 20

Pyruvate passes through the outer mitochondrial membrane by ________.

Accepted Answer

A) porin proteins 
B) passive transport 
C) pyruvate translocase 
D) simple diffusion through the lipid bilayer 
A) porin proteins 
B) passive transport 
C) pyruvate translocase 
D) simple diffusion through the lipid bilayer

Exam 13: The Citric Acid Cycle

The a-ketoglutarate and succinate dehydrogenase complexes are the only oligomeric enzymes used in the citric acid cycle.

ATP is consumed by the pyruvate dehydrogenase complex during the synthesis of acetyl CoA.

In citrus fruits,the levels of citric acid are related to its ability to conduct a citric acid cycle of reactions and not to its ability to act as a preservative or a reservoir of carbon.

The succinate dehydrogenase reaction is unusual for a dehydrogenase because it uses ________ as an electron acceptor (oxidizing agent)that is regenerated by ubiquinone.

The mechanism of pyruvate dehydrogenase complex is an example of channeling.

Citrate is chemically symmetric but is a prochiral molecule because the two acetyl groups are specifically oriented by the enzyme aconitase.

The succinate dehydrogenase complex catalyzes

Which enzyme is the same in both the pyruvate dehydrogenase and α-ketoglutarate complexes?

Please match the following reactions to their respective energy yielding products. Please note that a product may be used once,more than once,or not at all as an answer. -Isocitrate dehydrogenase

The pyruvate dehydrogenase complex is located inside mitochondria .Pyruvate is formed by glycolysis in the cytoplasm.Pyruvate is brought into the mitochondrion by

Which product of the citric acid cycle produces the most ATP equivalents?

Please match the following reactions to their respective energy yielding products. Please note that a product may be used once,more than once,or not at all as an answer. -Malate dehydrogenase

The activity of dihydrolipoamide acetyltransferase (E2)is inhibited when the concentration of acetyl CoA is decreased.

About how many total ATP equivalents are generated by the complete oxidation of one molecule of acetyl CoA?

All members of the aconitase family of proteins contain an iron sulfur cluster.

Which process is not implicated in the evolution of the citric acid cycle pathway?

The citric acid cycle is an anaerobic pathway that occurs in the mitochondria of eukaryotes.

Which of the following enzymatic reactions are examples of substrate level phosphorylation?

After passing through pyruvate dehydrogenase and the citric acid cycle,one mole of pyruvate will result in the formation of ________ moles of carbon dioxide and ________ mole(s)of ATP (or GTP).

Pyruvate passes through the outer mitochondrial membrane by ________.

Introduction to Biochemistry

Water

Amino Acids and the Primary Structures of Proteins

Proteins: Three-Dimensional Structure and Function

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Lipids and Membranes

Introduction to Metabolism

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

Electron Transport and Atp Synthesis

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

DNA Replication, repair, and Recombination

Transcription and RNA Processing

Protein Synthesis

Filters

After passing through pyruvate dehydrogenase and the citric acid cycle,one mole of pyruvate will result in the formation of moles of carbon dioxide and mole(s)of ATP (or GTP).