Question 1

Where are the proteins of the electron transport chain located?

Accepted Answer

A) cytosol 
B) mitochondrial outer membrane 
C) mitochondrial inner membrane 
D) mitochondrial intermembrane space 
E) mitochondrial matrix 
A) cytosol 
B) mitochondrial outer membrane 
C) mitochondrial inner membrane 
D) mitochondrial intermembrane space 
E) mitochondrial matrix C

Question 2

Why does glucose oxidation occur in a series of steps?

Accepted Answer

A) One step wouldn't allow the energy released to be harnessed efficiently. 
B) It doesn't have to; it just happens to be that way. 
C) Glycolysis evolved first and steps were just added over time. 
D) Glucose cannot pass into the mitochondria and oxygen cannot enter the cytosol. 
E) Glucose is reduced, not oxidized. 
A) One step wouldn't allow the energy released to be harnessed efficiently. 
B) It doesn't have to; it just happens to be that way. 
C) Glycolysis evolved first and steps were just added over time. 
D) Glucose cannot pass into the mitochondria and oxygen cannot enter the cytosol. 
E) Glucose is reduced, not oxidized. A

Question 3

In liver cells, the inner mitochondrial membranes are about five times the area of the outer mitochondrial membranes. What purpose must this serve?

Accepted Answer

A) It allows for an increased rate of glycolysis. 
B) It allows for an increased rate of the citric acid cycle. 
C) It increases the surface for oxidative phosphorylation. 
D) It increases the surface for substrate-level phosphorylation. 
E) It allows the liver cell to have fewer mitochondria. 
A) It allows for an increased rate of glycolysis. 
B) It allows for an increased rate of the citric acid cycle. 
C) It increases the surface for oxidative phosphorylation. 
D) It increases the surface for substrate-level phosphorylation. 
E) It allows the liver cell to have fewer mitochondria. C

Question 4

Use the following figure to answer the questions below.
   
The citric acid cycle.
-Starting with citrate, which of the following combinations of products would result from three acetyl CoA molecules entering the citric acid cycle (see the figure above)?

Accepted Answer

A) 1 ATP, 2 CO₂, 3 NADH, and 1 FADH₂ 
B) 2 ATP, 2 CO₂, 3 NADH, and 3 FADH₂ 
C) 3 ATP, 3 CO₂, 3 NADH, and 3 FADH₂ 
D) 3 ATP, 6 CO₂, 9 NADH, and 3 FADH₂ 
E) 38 ATP, 6 CO₂, 3 NADH, and 12 FADH₂ 
A) 1 ATP, 2 CO₂, 3 NADH, and 1 FADH₂ 
B) 2 ATP, 2 CO₂, 3 NADH, and 3 FADH₂ 
C) 3 ATP, 3 CO₂, 3 NADH, and 3 FADH₂ 
D) 3 ATP, 6 CO₂, 9 NADH, and 3 FADH₂ 
E) 38 ATP, 6 CO₂, 3 NADH, and 12 FADH₂

Question 5

Use the following information to answer the questions below.
In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate (1) loses a carbon, which is given off as a molecule of CO₂, (2) is oxidized to form a two-carbon compound called acetate, and (3) is bonded to coenzyme A.
-Why is coenzyme A, a sulphur-containing molecule derived from a B vitamin, added?

Accepted Answer

A) because sulphur is needed for the molecule to enter the mitochondrion 
B) in order to utilize this portion of a B vitamin that would otherwise be a waste product from another pathway 
C) to provide a relatively unstable molecule whose acetyl portion can be readily transferred to a compound in the citric acid cycle 
D) because it drives the reaction that regenerates NAD⁺ 
E) in order to remove one molecule of CO₂ 
A) because sulphur is needed for the molecule to enter the mitochondrion 
B) in order to utilize this portion of a B vitamin that would otherwise be a waste product from another pathway 
C) to provide a relatively unstable molecule whose acetyl portion can be readily transferred to a compound in the citric acid cycle 
D) because it drives the reaction that regenerates NAD⁺ 
E) in order to remove one molecule of CO₂

Question 6

During aerobic respiration, which of the following directly donates electrons to the electron transport chain at the lowest energy level?

Accepted Answer

A) NAD⁺ 
B) NADH 
C) ATP 
D) ADP +   ᵢ 
E) FADH₂ 
A) NAD⁺ 
B) NADH 
C) ATP 
D) ADP +   ᵢ 
E) FADH₂

Question 7

It is possible to prepare vesicles from portions of the inner mitochondrial membrane. Which one of the following processes could still be carried on by this isolated inner membrane?

Accepted Answer

A) the citric acid cycle 
B) oxidative phosphorylation 
C) glycolysis and fermentation 
D) reduction of NAD⁺ 
E) both the citric acid cycle and oxidative phosphorylation 
A) the citric acid cycle 
B) oxidative phosphorylation 
C) glycolysis and fermentation 
D) reduction of NAD⁺ 
E) both the citric acid cycle and oxidative phosphorylation

Question 8

Use the following information to answer the questions below.
You have collected samples from mud at the bottom of a nearby pond and have isolated different bacteria and protists from that community. You put the cultures in appropriate media in test tubes with loose-fitting lids and leave for the night, confident that your cultures will be growing well when you return.
-Test tube B has a strong smell of rotten eggs. This culture must contain

Accepted Answer

A) obligate aerobes. 
B) obligate anaerobes. 
C) facultative anaerobes. 
D) sulphate-reducing bacteria. 
E) fermenting organisms. 
A) obligate aerobes. 
B) obligate anaerobes. 
C) facultative anaerobes. 
D) sulphate-reducing bacteria. 
E) fermenting organisms.

Question 9

The transport of pyruvate into mitochondria depends on the proton-motive force across the inner mitochondrial membrane. How does pyruvate enter the mitochondrion?

Accepted Answer

A) active transport 
B) diffusion 
C) facilitated diffusion 
D) through a channel 
E) through a pore 
A) active transport 
B) diffusion 
C) facilitated diffusion 
D) through a channel 
E) through a pore

Question 10

Which of the following occurs in the cytosol of a eukaryotic cell?

Accepted Answer

A) glycolysis and fermentation 
B) fermentation and chemiosmosis 
C) oxidation of pyruvate to acetyl CoA 
D) citric acid cycle 
E) oxidative phosphorylation 
A) glycolysis and fermentation 
B) fermentation and chemiosmosis 
C) oxidation of pyruvate to acetyl CoA 
D) citric acid cycle 
E) oxidative phosphorylation

Question 11

The primary role of oxygen in cellular respiration is to

Accepted Answer

A) yield energy in the form of ATP as it is passed down the respiratory chain. 
B) act as an acceptor for electrons and hydrogen, forming water. 
C) combine with carbon, forming CO₂. 
D) combine with lactate, forming pyruvate. 
E) catalyze the reactions of glycolysis. 
A) yield energy in the form of ATP as it is passed down the respiratory chain. 
B) act as an acceptor for electrons and hydrogen, forming water. 
C) combine with carbon, forming CO₂. 
D) combine with lactate, forming pyruvate. 
E) catalyze the reactions of glycolysis.

Question 12

Use the following information to answer the questions below.
A young animal has never had much energy. He is brought to a veterinarian for help and is sent to the animal hospital for some tests. There they discover his mitochondria can use only fatty acids and amino acids for respiration, and his cells produce more lactate than normal.
-Of the following, which is the best explanation of his condition?

Accepted Answer

A) His mitochondria lack the transport protein that moves pyruvate across the outer mitochondrial membrane. 
B) His cells cannot move NADH from glycolysis into the mitochondria. 
C) His cells contain something that inhibits oxygen use in his mitochondria. 
D) His cells lack the enzyme in glycolysis that forms pyruvate. 
E) His cells have a defective electron transport chain, so glucose goes to lactate instead of to acetyl CoA. 
A) His mitochondria lack the transport protein that moves pyruvate across the outer mitochondrial membrane. 
B) His cells cannot move NADH from glycolysis into the mitochondria. 
C) His cells contain something that inhibits oxygen use in his mitochondria. 
D) His cells lack the enzyme in glycolysis that forms pyruvate. 
E) His cells have a defective electron transport chain, so glucose goes to lactate instead of to acetyl CoA.

Question 13

An electron loses potential energy when it

Accepted Answer

A) shifts to a less electronegative atom. 
B) shifts to a more electronegative atom. 
C) increases its kinetic energy. 
D) increases its activity as an oxidizing agent. 
E) ᵐᵒᵛᵉˢ ᶠᵃʳᵗʰᵉʳ ᵃʷᵃʸ ᶠʳᵒᵐ ᵗʰᵉ ⁿᵘᶜˡᵉᵘˢ ᵒᶠ ᵗʰᵉ ᵃᵗᵒᵐ. 
A) shifts to a less electronegative atom. 
B) shifts to a more electronegative atom. 
C) increases its kinetic energy. 
D) increases its activity as an oxidizing agent. 
E) ᵐᵒᵛᵉˢ ᶠᵃʳᵗʰᵉʳ ᵃʷᵃʸ ᶠʳᵒᵐ ᵗʰᵉ ⁿᵘᶜˡᵉᵘˢ ᵒᶠ ᵗʰᵉ ᵃᵗᵒᵐ.

Question 14

When an individual is exercising heavily and when the muscle becomes oxygen-deprived, muscle cells convert pyruvate to lactate. What happens to the lactate in skeletal muscle cells?

Accepted Answer

A) It is converted to NAD⁺. 
B) It produces CO₂ and water. 
C) It is taken to the liver and converted back to pyruvate. 
D) It reduces FADH₂ to FAD⁺. 
E) It is converted to alcohol. 
A) It is converted to NAD⁺. 
B) It produces CO₂ and water. 
C) It is taken to the liver and converted back to pyruvate. 
D) It reduces FADH₂ to FAD⁺. 
E) It is converted to alcohol.

Question 15

When skeletal muscle cells undergo anaerobic respiration, they become fatigued and painful. This is now known to be caused by

Accepted Answer

A) buildup of pyruvate. 
B) buildup of lactate. 
C) increase in sodium ions. 
D) increase in potassium ions. 
E) increase in ethanol. 
A) buildup of pyruvate. 
B) buildup of lactate. 
C) increase in sodium ions. 
D) increase in potassium ions. 
E) increase in ethanol.

Question 16

An organism is discovered that thrives both in the presence and absence of oxygen in the air. Curiously, the consumption of sugar increases as oxygen is removed from the organism's environment, even though the organism does not gain much weight. This organism

Accepted Answer

A) must use a molecule other than oxygen to accept electrons from the electron transport chain. 
B) is a normal eukaryotic organism. 
C) is photosynthetic. 
D) is an anaerobic organism. 
E) is a facultative anaerobe. 
A) must use a molecule other than oxygen to accept electrons from the electron transport chain. 
B) is a normal eukaryotic organism. 
C) is photosynthetic. 
D) is an anaerobic organism. 
E) is a facultative anaerobe.

Question 17

Use the following figure to answer the questions below.
  
-Which of the following most accurately describes what is happening along the electron transport chain in the figure above?

Accepted Answer

A) Chemiosmosis is coupled with electron transfer. 
B) Each electron carrier alternates between being reduced and being oxidized. 
C) ATP is generated at each step. 
D) Energy of the electrons increases at each step. 
E) Molecules in the chain give up some of their potential energy. 
A) Chemiosmosis is coupled with electron transfer. 
B) Each electron carrier alternates between being reduced and being oxidized. 
C) ATP is generated at each step. 
D) Energy of the electrons increases at each step. 
E) Molecules in the chain give up some of their potential energy.

Question 18

In alcohol fermentation, NAD⁺ is regenerated from NADH by

Accepted Answer

A) reduction of acetaldehyde to ethanol (ethyl alcohol). 
B) oxidation of pyruvate to acetyl CoA. 
C) reduction of pyruvate to form lactate. 
D) oxidation of ethanol to acetyl CoA. 
E) reduction of ethanol to pyruvate. 
A) reduction of acetaldehyde to ethanol (ethyl alcohol). 
B) oxidation of pyruvate to acetyl CoA. 
C) reduction of pyruvate to form lactate. 
D) oxidation of ethanol to acetyl CoA. 
E) reduction of ethanol to pyruvate.

Question 19

When a molecule of NAD⁺ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a proton), the molecule becomes

Accepted Answer

A) dehydrogenated. 
B) oxidized. 
C) reduced. 
D) redoxed. 
E) hydrolyzed. 
A) dehydrogenated. 
B) oxidized. 
C) reduced. 
D) redoxed. 
E) hydrolyzed.

Question 20

Why does the oxidation of organic compounds by molecular oxygen to produce CO₂ and water release free energy?

Accepted Answer

A) The covalent bonds in organic molecules and molecular oxygen have more kinetic energy than the covalent bonds in water and carbon dioxide. 
B) Electrons are being moved from atoms that have a lower affinity for electrons (such as 
C) to atoms with a higher affinity for electrons (such as O). 
C) The oxidation of organic compounds can be used to make ATP. 
D) The electrons have a higher potential energy when associated with water and CO₂ than they do in organic compounds. 
E) The covalent bond in O2 is unstable and easily broken by electrons from organic molecules. 
A) The covalent bonds in organic molecules and molecular oxygen have more kinetic energy than the covalent bonds in water and carbon dioxide. 
B) Electrons are being moved from atoms that have a lower affinity for electrons (such as 
C) to atoms with a higher affinity for electrons (such as O). 
C) The oxidation of organic compounds can be used to make ATP. 
D) The electrons have a higher potential energy when associated with water and CO₂ than they do in organic compounds. 
E) The covalent bond in O2 is unstable and easily broken by electrons from organic molecules.

Exam 9: Cellular Respiration and Fermentation

Where are the proteins of the electron transport chain located?

Why does glucose oxidation occur in a series of steps?

In liver cells, the inner mitochondrial membranes are about five times the area of the outer mitochondrial membranes. What purpose must this serve?

Use the following figure to answer the questions below. The citric acid cycle. -Starting with citrate, which of the following combinations of products would result from three acetyl CoA molecules entering the citric acid cycle (see the figure above)?

During aerobic respiration, which of the following directly donates electrons to the electron transport chain at the lowest energy level?

It is possible to prepare vesicles from portions of the inner mitochondrial membrane. Which one of the following processes could still be carried on by this isolated inner membrane?

The transport of pyruvate into mitochondria depends on the proton-motive force across the inner mitochondrial membrane. How does pyruvate enter the mitochondrion?

Which of the following occurs in the cytosol of a eukaryotic cell?

The primary role of oxygen in cellular respiration is to

An electron loses potential energy when it

When an individual is exercising heavily and when the muscle becomes oxygen-deprived, muscle cells convert pyruvate to lactate. What happens to the lactate in skeletal muscle cells?

When skeletal muscle cells undergo anaerobic respiration, they become fatigued and painful. This is now known to be caused by

An organism is discovered that thrives both in the presence and absence of oxygen in the air. Curiously, the consumption of sugar increases as oxygen is removed from the organism's environment, even though the organism does not gain much weight. This organism

Use the following figure to answer the questions below. -Which of the following most accurately describes what is happening along the electron transport chain in the figure above?

In alcohol fermentation, NAD⁺ is regenerated from NADH by

When a molecule of NAD⁺ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a proton), the molecule becomes

Why does the oxidation of organic compounds by molecular oxygen to produce CO₂ and water release free energy?

Introduction: Evolution and Themes of Biology

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Regulation of Gene Expression

Viruses

Dna Tools and Biotechnology

Genomes and Their Evolution

Descent With Modification: a Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity Ii: the Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Plant Structure, Growth, and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signalling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

Filters