Question 1

What molecule can oxidize NADH?

Accepted Answer

A) Acetaldehyde 
B) Lactate 
C) Ubiquinone 
D) Glucose 
A) Acetaldehyde 
B) Lactate 
C) Ubiquinone 
D) Glucose A

Question 2

All of the reactions of cellular respiration that occur after glycolysis take place in what part of the eukaryotic cell?

Accepted Answer

A) The chloroplast 
B) The nucleus 
C) The mitochondria 
D) The plasma membrane 
A) The chloroplast 
B) The nucleus 
C) The mitochondria 
D) The plasma membrane C

Question 3

In order to lose weight and reduce body fat, a friend of yours has decided to eliminate all fat from his diet, while consuming unrestricted amounts of carbohydrates.What do you think of this idea?

Accepted Answer

A) It is a good idea, because if your friend doesn't eat any fat, he cannot store any additional fat. 
B) It is a bad idea, because consumption of fat is required to provide cofactors for the electron transport chain. 
C) It is a good idea, because under conditions where ATP levels are low in cells, carbohydrates will be stored, and fat stores will be catabolized via beta-oxidation to generate energy. 
D) It is a bad idea, because if ATP levels are high in cells, excess acetyl-CoA from the metabolism of carbohydrates can be used for fatty acid synthesis. 
A) It is a good idea, because if your friend doesn't eat any fat, he cannot store any additional fat. 
B) It is a bad idea, because consumption of fat is required to provide cofactors for the electron transport chain. 
C) It is a good idea, because under conditions where ATP levels are low in cells, carbohydrates will be stored, and fat stores will be catabolized via beta-oxidation to generate energy. 
D) It is a bad idea, because if ATP levels are high in cells, excess acetyl-CoA from the metabolism of carbohydrates can be used for fatty acid synthesis. D

Question 4

Arsenic poisoning can lead to organ failure and death.Though arsenic can inhibit or interfere with a number of cellular enzymes, arsenic poisoning is thought to be mainly due to indirect inhibition of enzymes involved in both pyruvate oxidation and the Krebs cycle.As a result, this compound must be able to enter which cellular compartment?

Accepted Answer

A) The cytoplasm 
B) The nucleus 
C) The intermembrane space of the mitochondria 
D) The mitochondrial matrix 
A) The cytoplasm 
B) The nucleus 
C) The intermembrane space of the mitochondria 
D) The mitochondrial matrix

Question 5

Regardless of the electron or hydrogen acceptor used, one of the products of fermentation is always

Accepted Answer

A) ADP. 
B) ATP. 
C) NAD+. 
D) pyruvate. 
A) ADP. 
B) ATP. 
C) NAD+. 
D) pyruvate.

Question 6

Many of the antiviral drugs currently used to treat HIV/AIDS also interfere with an enzyme that helps mitochondria multiply.Treatment can therefore result in a decrease in the number of mitochondria found in certain tissues.Given this information, what might you expect to see in patients treated with antiviral drugs?

Accepted Answer

A) An increase in oxidative phosphorylation 
B) An increase in phosphofructokinase activity 
C) An increase in NADH dehydrogenase activity 
D) An increase in lactic acid levels 
A) An increase in oxidative phosphorylation 
B) An increase in phosphofructokinase activity 
C) An increase in NADH dehydrogenase activity 
D) An increase in lactic acid levels

Question 7

To form NADH from NAD+, two electrons and a proton are removed from an organic molecule.What term best describes the reaction in which electrons and a proton are removed from an organic molecule?

Accepted Answer

A) Condensation 
B) Reduction 
C) Dehydrogenation 
D) Decarboxylation 
A) Condensation 
B) Reduction 
C) Dehydrogenation 
D) Decarboxylation

Question 8

How and where is ATP made in a eukaryotic cell?

Accepted Answer

A) ATP is only made in the mitochondria in response to chemiosmosis. 
B) ATP is made in all compartments of the cell in response to endergonic reactions and is used to drive exergonic reactions in the cell. 
C) ATP can be made by direct phosphorylation of ADP in the cytoplasm, and by an enzyme complex that uses the energy from a proton gradient to drive ATP synthesis in the mitochondria.It can also be made in other locations in the cell, depending on the cell type. 
D) ATP can be made by an enzyme complex that uses the energy of protons moving down their concentration gradient from the mitochondrial matrix to the cytoplasm to make the ATP. 
A) ATP is only made in the mitochondria in response to chemiosmosis. 
B) ATP is made in all compartments of the cell in response to endergonic reactions and is used to drive exergonic reactions in the cell. 
C) ATP can be made by direct phosphorylation of ADP in the cytoplasm, and by an enzyme complex that uses the energy from a proton gradient to drive ATP synthesis in the mitochondria.It can also be made in other locations in the cell, depending on the cell type. 
D) ATP can be made by an enzyme complex that uses the energy of protons moving down their concentration gradient from the mitochondrial matrix to the cytoplasm to make the ATP.

Question 9

As a forensic pathologist, you have just completed an autopsy of a poisoning victim.After a thorough examination, you conclude that the victim died of cyanide poisoning.You know that cyanide binds to the cytochrome oxidase complex, and therefore list the official cause of death as suffocation due to cyanide exposure.However, if you wanted to provide a more technical explanation as to the cause of death, which process was specifically inhibited directly by cyanide?

Accepted Answer

A) The reduction of NAD+ 
B) The oxidation of FADH2 
C) All proton pumping into the intermembrane space 
D) The formation of water from oxygen 
A) The reduction of NAD+ 
B) The oxidation of FADH2 
C) All proton pumping into the intermembrane space 
D) The formation of water from oxygen

Question 10

You decide to go on vacation in the mountains, where you are staying in a cabin.Unfortunately, when you turn on the water in the cabin you smell hydrogen sulfide (H2S) gas.After some research, you find out that the H2S may be due to the presence of sulfur bacteria living in your pipes.What molecule do these bacteria use as an electron acceptor?

Accepted Answer

A) O2 
B) H20 
C) SO4 
D) H2S 
A) O2 
B) H20 
C) SO4 
D) H2S

Question 11

If citrate levels are high in the cell, but ATP levels are low, what do you think will happen in the cell?

Accepted Answer

A) In the presence of glucose, glycolysis will run to generate energy for the cell, but the Krebs cycle will be inhibited. 
B) Glycolysis will be inhibited, but the Krebs cycle will be functional, allowing it to be utilized to breakdown acetyl-CoA generated from beta-oxidation. 
C) The electron transport chain will be inhibited, causing a build-up of NADH and FADH2.This will inhibit the Krebs cycle, but in the presence of glucose, glycolysis will still run coupled with fermentation to regenerate NAD+. 
D) Glycolysis and the Krebs cycle will both be inhibited, thus under these conditions there will be no mechanism to generate ATP. 
A) In the presence of glucose, glycolysis will run to generate energy for the cell, but the Krebs cycle will be inhibited. 
B) Glycolysis will be inhibited, but the Krebs cycle will be functional, allowing it to be utilized to breakdown acetyl-CoA generated from beta-oxidation. 
C) The electron transport chain will be inhibited, causing a build-up of NADH and FADH2.This will inhibit the Krebs cycle, but in the presence of glucose, glycolysis will still run coupled with fermentation to regenerate NAD+. 
D) Glycolysis and the Krebs cycle will both be inhibited, thus under these conditions there will be no mechanism to generate ATP.

Question 12

What important metabolic intermediate does not cross the inner membrane of the mitochondria?

Accepted Answer

A) ATP 
B) Acetyl-CoA 
C) Pyruvate 
D) Oxygen 
A) ATP 
B) Acetyl-CoA 
C) Pyruvate 
D) Oxygen

Question 13

In the absence of oxygen, can cells utilize the electron transport chain?

Accepted Answer

A) Yes, all cells can make use of the electron transport chain in the absence of oxygen via fermentation. 
B) No, oxygen is a required cofactor for the complexes in the electron transport chain. 
C) Yes, in the case that a cell can use a terminal electron acceptor other than oxygen, it can make use of the electron transport chain. 
D) No, oxygen is the primary electron acceptor in electron transport chains in all cell types. 
A) Yes, all cells can make use of the electron transport chain in the absence of oxygen via fermentation. 
B) No, oxygen is a required cofactor for the complexes in the electron transport chain. 
C) Yes, in the case that a cell can use a terminal electron acceptor other than oxygen, it can make use of the electron transport chain. 
D) No, oxygen is the primary electron acceptor in electron transport chains in all cell types.

Question 14

What happens to the oxygen that is used in cellular respiration?

Accepted Answer

A) It is converted to carbon dioxide 
B) It is used to make glucose 
C) It is used to make Krebs cycle intermediates 
D) It is reduced to form water 
A) It is converted to carbon dioxide 
B) It is used to make glucose 
C) It is used to make Krebs cycle intermediates 
D) It is reduced to form water

Question 15

Cytochromes contain a heme group similar to that in hemoglobin.The iron atom (Fe) in the center of the group can be oxidized and reduced.If someone was suffering from iron deficiency anemia, what stage of cellular respiration would be most affected?

Accepted Answer

A) Glycolysis 
B) The Krebs cycle 
C) The electron transport chain 
D) Fermentation 
A) Glycolysis 
B) The Krebs cycle 
C) The electron transport chain 
D) Fermentation

Question 16

What must happen to amino acids before they can be used in catabolic reactions?

Accepted Answer

A) They must be decarboxylated 
B) They must be deoxygenated 
C) They must be dehydrogenated 
D) They must be deaminated 
A) They must be decarboxylated 
B) They must be deoxygenated 
C) They must be dehydrogenated 
D) They must be deaminated

Question 17

What oxidizing agent is used to temporarily store high energy electrons harvested from glucose molecules in a series of gradual steps in the cytoplasm?

Accepted Answer

A) FADH2 
B) ADP 
C) NAD+ 
D) Oxygen 
A) FADH2 
B) ADP 
C) NAD+ 
D) Oxygen

Question 18

In the reaction catalyzed by aconitase, the conversion of citrate to isocitrate is inhibited by fluoroacetate.Fluoroacetate is used as a pesticide.Why is this an effective pesticide?

Accepted Answer

A) It inhibits glycolysis 
B) It inhibits pyruvate oxidation 
C) It inhibits the Krebs cycle 
D) It inhibits the electron transport chain 
A) It inhibits glycolysis 
B) It inhibits pyruvate oxidation 
C) It inhibits the Krebs cycle 
D) It inhibits the electron transport chain

Question 19

What is the oxidized form of the most common electron carrier that is needed for both glycolysis and the Krebs cycle?

Accepted Answer

A) ATP 
B) FAD 
C) pyruvate 
D) NAD+ 
A) ATP 
B) FAD 
C) pyruvate 
D) NAD+

Question 20

The energy released in the mitochondrial electron transport chain is used to transport proteins into the.

Accepted Answer

A) mitochondrial matrix. 
B) cytoplasm. 
C) endoplasmic reticulum. 
D) intermembrane space of the mitochondria. 
A) mitochondrial matrix. 
B) cytoplasm. 
C) endoplasmic reticulum. 
D) intermembrane space of the mitochondria.

Exam 7: How Cells Harvest Energy

What molecule can oxidize NADH?

All of the reactions of cellular respiration that occur after glycolysis take place in what part of the eukaryotic cell?

In order to lose weight and reduce body fat, a friend of yours has decided to eliminate all fat from his diet, while consuming unrestricted amounts of carbohydrates.What do you think of this idea?

Regardless of the electron or hydrogen acceptor used, one of the products of fermentation is always

To form NADH from NAD+, two electrons and a proton are removed from an organic molecule.What term best describes the reaction in which electrons and a proton are removed from an organic molecule?

How and where is ATP made in a eukaryotic cell?

If citrate levels are high in the cell, but ATP levels are low, what do you think will happen in the cell?

What important metabolic intermediate does not cross the inner membrane of the mitochondria?

In the absence of oxygen, can cells utilize the electron transport chain?

What happens to the oxygen that is used in cellular respiration?

Cytochromes contain a heme group similar to that in hemoglobin.The iron atom (Fe) in the center of the group can be oxidized and reduced.If someone was suffering from iron deficiency anemia, what stage of cellular respiration would be most affected?

What must happen to amino acids before they can be used in catabolic reactions?

What oxidizing agent is used to temporarily store high energy electrons harvested from glucose molecules in a series of gradual steps in the cytoplasm?

In the reaction catalyzed by aconitase, the conversion of citrate to isocitrate is inhibited by fluoroacetate.Fluoroacetate is used as a pesticide.Why is this an effective pesticide?

What is the oxidized form of the most common electron carrier that is needed for both glycolysis and the Krebs cycle?

The energy released in the mitochondrial electron transport chain is used to transport proteins into the.

The Science of Biology

The Nature of Molecules and the Properties of Water

The Chemical Building Blocks of Life

Cell Structure

Membranes

Energy and Metabolism

Photosynthesis

Cell Communication

How Cells Divide

Sexual Reproduction and Meiosis

Patterns of Inheritance

Chromosomes, Mapping, and the Meiosis-Inheritance Connection

Dna: the Genetic Material

Genes and How They Work

Control of Gene Expression

Biotechnology

Genomics

Cellular Mechanisms of Development

Genes Within Populations

The Evidence for Evolution

The Origin of Species

Systematics, Phylogenies, and Comparative Biology

Genome Evolution

Evolution of Development

The Origin and Diversity of Life

Viruses

Prokaryotes

Protists

Seedless Plants

Seed Plants

Fungi

Animal Diversity and the Evolution of Body Plans

Protostomes

Deuterostomes

Plant Form

Transport in Plants

Plant Nutrition and Soils

Plant Defense Responses

Sensory Systems in Plants

Plant Reproduction

The Animal Body and Principles of Regulation

The Nervous System

Sensory Systems

The Endocrine System

The Musculoskeletal System

The Digestive System

The Respiratory System

The Circulatory System

Osmotic Regulation and the Urinary System

The Immune System

The Reproductive System

Animal Development

Behavioral Biology

Ecology of Individuals and Populations

Community Ecology

Dynamics of Ecosystems

The Biosphere

Conservation Biology

Filters

To form NADH from NAD⁺, two electrons and a proton are removed from an organic molecule.What term best describes the reaction in which electrons and a proton are removed from an organic molecule?