Deck 6: How Cells Harvest Chemical Energy

Question 1

A kilocalorie is defined as

A) the quantity of glucose needed to increase the body temperature by 1°C.
B) the quantity of heat needed to raise the temperature of 1 kg of water by 1°C.
C) the quantity of food used to maintain normal bodily functions.
D) the quantity of food consumed during a given type of exercise.

Answer 1

B

Question 2

Which of the following are products of cellular respiration?

A) oxygen and carbon dioxide
B) energy to make ATP and carbon dioxide and water
C) oxygen and glucose
D) oxygen and energy to make ATP

Answer 2

B

Question 3

Humans use about ________ of their daily calories to maintain brain cells and power other life-sustaining activities.

A) 25%
B) 50%
C) 75%
D) 90%

Answer 3

C

Question 4

Oxidation is the ________, and reduction is the ________.

A) gain of electrons; loss of electrons
B) loss of electrons; gain of electrons
C) gain of oxygen; loss of oxygen
D) gain of protons; loss of protons

Question 5

During redox reactions,

A) the loss of electrons from one molecule is called reduction.
B) electrons are lost from one substance and added to another substance.
C) protons from one molecule replace the electrons lost from another molecule.

Question 6

The label on the box of breakfast cereal lists one serving as containing "200 Calories" per serving. How many calories are actually in one serving?

A) 20
B) 2,000
C) 200,000
D) 2,000,000

Question 7

How do cells capture the energy released by cellular respiration?

A) They produce ATP.
B) They produce glucose.
C) They store energy in molecules of carbon dioxide.
D) The energy is coupled to oxygen.

Question 8

During cellular respiration, energy in glucose

A) becomes stored in molecules of ammonia.
B) is used to manufacture glucose.
C) is released all at once.
D) is carried by electrons.

Question 9

During cellular respiration, NADH

A) is chemically converted into ATP.
B) is reduced to form NAD+.
C) delivers its electron load to the first electron carrier molecule.
D) is the final electron acceptor.

Question 10

A drug is tested in the laboratory and is found to create holes in both mitochondrial membranes. Scientists suspect that the drug will be harmful to human cells because it will inhibit

A) the citric acid cycle only.
B) oxidative phosphorylation only.
C) glycolysis only.
D) the citric acid cycle and oxidative phosphorylation.

Question 11

Which of the following statements about the energy yields from cellular respiration is true?

A) Cellular respiration is more efficient at harnessing energy from glucose than car engines are at harnessing energy from gasoline.
B) Cellular respiration converts all of the energy in glucose into energy in ATP.
C) Cellular respiration converts the kinetic energy of glucose into chemical energy.
D) The heat produced during cellular respiration is only a tiny fraction of the chemical energy available in a glucose molecule.

Question 12

The processes of photosynthesis and cellular respiration are complementary. During these energy conversions, some energy is

A) lost in the form of heat.
B) used to create light.
C) destroyed when the chemical bonds of glucose are made.
D) saved in the chemical bonds of water, CO2, and O2.

Question 13

In biological systems, an important enzyme involved in the regulation of redox reactions is

A) glucose.
B) dehydrogenase.
C) oxygen.
D) ATP.

Question 14

Which of the following metabolic pathways is common in aerobic and anaerobic metabolism?

A) the citric acid cycle
B) oxidative phosphorylation
C) glycolysis
D) electron transport chain

Question 15

Which of the following statements regarding photosynthesis and cellular respiration is true?

A) Photosynthesis occurs in chloroplasts, and cellular respiration occurs in mitochondria.
B) Photosynthesis occurs in mitochondria, and cellular respiration occurs in chloroplasts.
C) Photosynthesis occurs in mitochondria and in chloroplasts.
D) Cellular respiration occurs in mitochondria and in chloroplasts.

Question 16

Which of the following statements regarding the movement of electrons during cellular respiration is true?

A) Electrons tend to move away from O2.
B) O2 is eventually oxidized by the electrons to form water.
C) The electrons release large amounts of energy each time they are transferred from one molecule to another.
D) O2 is reduced when it accepts electrons and forms water.

Question 17

The overall equation for the cellular respiration of glucose is

A) C5H12O6 + 6 O2 → 5 CO2 + 6 H2O + energy.
B) 5 CO2 + 6 H2O → C5H12O6 + 6 O2 + energy.
C) C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + energy.
D) C6H12O6 + energy → 6 CO2+ 6 H2O + 6 O2.

Question 18

Respiration ________, and cellular respiration ________.

A) produces ATP; is gas exchange
B) is gas exchange; produces ATP
C) produces glucose; produces oxygen
D) uses glucose; produces glucose

Question 19

During which of the following phases of cellular respiration does substrate-level phosphorylation take place?

A) glycolysis only
B) the citric acid cycle only
C) oxidative phosphorylation only
D) glycolysis and the citric acid cycle

Question 20

Humans use the calories they obtain from ________ as their source of energy.

A) food
B) water
C) sunlight
D) minerals

Question 21

At the end of the citric acid cycle, most of the energy remaining from the original glucose is stored in

A) CO2.
B) pyruvate.
C) ATP.
D) NADH.

Question 22

Which of the following statements about the inner mitochondrial membrane is false?

A) ATP synthase is found in the inner mitochondrial membrane.
B) The inner mitochondrial membrane plays a role in the production of pyruvate.
C) Electron carriers are found in the inner mitochondrial membrane.
D) A gradient of H+ exists across the inner mitochondrial membrane.

Question 23

A culture of bacteria is fed glucose containing radioactive carbon and is then examined. During the citric acid cycle, radioactive carbon would first appear in

A) NADH.
B) citrate.
C) oxaloacetate.
D) CO2.

Question 24

Which of the following is a result of glycolysis?

A) production of CO2
B) conversion of glucose to two three-carbon compounds
C) a net loss of two ATPs per glucose molecule
D) conversion of NADH to NAD+

Question 25

After glycolysis but before the citric acid cycle

A) pyruvate is oxidized.
B) a carbon atom is added to pyruvate to make a four-carbon compound.
C) coenzyme A is cleaved off pyruvate.
D) glucose is split, producing two molecules of pyruvate.

Question 26

Rotenone is a poison commonly added to insecticides. Rotenone binds tightly with one of the electron carrier molecules in the electron transport chain, preventing electrons from passing to the next carrier molecule. Insects exposed to rotenone will die because

A) they will no longer be able to perform anaerobic respiration.
B) high levels of fermentation products will build up in their bodies.
C) they will no longer be able to produce adequate amounts of ATP.
D) they will no longer be able to absorb water and will become dehydrated.

Question 27

The mitochondrial cristae are an adaptation that

A) permits the expansion of mitochondria as oxygen accumulates in the mitochondrial matrix.
B) helps mitochondria divide during times of greatest cellular respiration.
C) increases the space for more copies of the electron transport chain and ATP synthase complexes.
D) carefully encloses the DNA housed within the mitochondrial matrix.

Question 28

A mutant protist is found in which some mitochondria lack an inner mitochondrial membrane. Which of the following pathways would be completely disrupted in these mitochondria?

A) oxidative phosphorylation
B) alcoholic fermentation
C) glycolysis

Question 29

The enzymes of the citric acid cycle are located in the

A) cytoplasm.
B) outer mitochondrial membrane.
C) nucleus.
D) mitochondrial matrix and inner mitochondrial membrane.

Question 30

Which of the following statements regarding the chemical grooming of pyruvate is false?

A) Two molecules of pyruvate are each converted into two-carbon molecules joined to a coenzyme A molecule.
B) Each pyruvate loses a carbon atom, which is released as CO2.
C) Two pyruvate molecules together contain less chemical energy than was found in the original glucose molecule.
D) Each pyruvate molecule has a CO2 added and then joins with an NADH.

Question 31

The end products of the citric acid cycle include all of the following except

A) CO2.
B) pyruvate.
C) ATP.
D) FADH2.

Question 32

In the electron transport chain, the final electron acceptor is

A) oxygen
B) carbon dioxide.
C) water.
D) ADP.

Question 33

By-products of cellular respiration include

A) oxygen and heat.
B) carbon dioxide and water.
C) FADH2 and NADH.
D) NADH and ATP.

Question 34

The end products of glycolysis include

A) NADH.
B) acetyl CoA.
C) citric acid.
D) O2.

Question 35

As electrons move through the mitochondrial space

A) NADH is reduced.
B) water is oxidized.
C) ATP synthase works by active transport.
D) the pH of the intermembrane space changes.

Question 36

How many molecules of NADH are produced during one round of glycolysis?

A) 2
B) 4
C) 6
D) 8

Question 37

Pyruvate

A) forms at the end of glycolysis.
B) is the molecule that starts the citric acid cycle.
C) is the end product of oxidative phosphorylation.
D) is a six-carbon molecule.

Question 38

The function of coenzyme A in the citric acid cycle is most like

A) a limousine driver dropping off a couple at the school prom.
B) a frog that turns into a prince.
C) a kid jumping up and down on a trampoline.
D) throwing a baited hook into a lake and catching a fish.

Question 39

During chemiosmosis,

A) energy is released as H+ ions move freely across mitochondrial membranes.
B) ATP is synthesized when H+ ions move through a channel in ATP synthase.
C) a concentration gradient is generated when large numbers of H+ ions are passively transported from the matrix of the mitochondrion to the mitochondrion's intermembrane space.
D) H+ ions serve as the final electron acceptor.

Question 40

As a result of glycolysis, there is a net gain of ________ ATP(s).

A) 0
B) 1
C) 2
D) 36

Question 41

Bacteria that are unable to survive in the presence of oxygen are called

A) obligate anaerobes.
B) obligate aerobes.
C) facultative anaerobes.

Question 42

Which of the following statements regarding food is false?

A) Food provides the raw materials for biosynthetic pathways that make molecules for cellular repair and growth.
B) Food provides the raw materials for biosynthetic pathways that can produce molecules that are not actually present in the original food.
C) Food provides the raw materials for biosynthetic pathways that can produce sugar by a process that is the exact opposite of glycolysis.
D) Food provides the raw materials for biosynthetic pathways that consume ATP.

Question 43

The energy yield from the breakdown of a single molecule of glucose does not depend upon

A) whether the NADH produced in glycolysis passes its electrons across the mitochondrial membrane to NAD+ or FAD.
B) the supply of oxygen.
C) the supply of carbon dioxide.
D) whether some of the energy of the H+ gradient is used for work other than ATP production.

Question 44

Which of the following statements regarding glycolysis is false?

A) Glycolysis is considered to be an ancient metabolic process because it does not require oxygen.
B) Glycolysis is considered to be an ancient metabolic process because it is not located in a membrane-bound organelle.
C) Glycolysis is considered to be an ancient metabolic system because it occurs universally.
D) Glycolysis is considered to be an ancient metabolic system because it is the most efficient metabolic pathway for ATP synthesis.

Question 45

A child is born with a rare disease in which mitochondria are missing from skeletal muscle cells. However, the muscles still function. Physicians find that the

A) muscles contain large amounts of lactate following even mild physical exercise.
B) muscles contain large amounts of carbon dioxide following even mild physical exercise.
C) muscles require extremely high levels of oxygen to function.
D) muscle cells cannot split glucose to pyruvate.

Question 46

Yeasts can produce ATP by either fermentation or oxidative phosphorylation; thus, they are

A) strict anaerobes.
B) strict aerobes.
C) facultative anaerobes.
D) facultative aerobes.

Question 47

When proteins are used as a source of energy for the body, the proteins

A) are converted into glucose molecules, which are fed into glycolysis.
B) are converted mainly into intermediates of glycolysis or the citric acid cycle.
C) donate electrons directly to the electron transport chain.
D) are hydrolyzed to glucose and converted to acetyl CoA, which enters the citric acid cycle.

Question 48

To obtain energy from starch and glycogen, the body must begin by

A) hydrolyzing the starch to glucose and the glycogen to amino acids.
B) hydrolyzing both starch and glycogen to glucose.
C) converting both starch and glycogen to fatty acids.
D) removing one glucose at a time with a condensation reaction.

Question 49

When did the level of oxygen in Earth's atmosphere become high enough to sustain aerobic respiration?

A) 1.0 billion years ago
B) 1.5 billion years ago
C) 2.7 billion years ago
D) 3.5 billion years ago

Question 50

When an organism such as a yeast lives by fermentation, it converts the pyruvate from glycolysis into a different compound, such as alcohol. Why doesn't it secrete the pyruvate directly?

A) The conversion yields 32 ATP per pyruvate molecule.
B) The conversion yields 1 NADH per pyruvate molecule.
C) The conversion is needed to regenerate the molecules needed for glycolysis.
D) A buildup of pyruvate in the surrounding environment would be too toxic.

Question 51

Which of the following organisms can make organic molecules from water and carbon dioxide?

A) bear
B) mushroom
C) wheat
D) crayfish

Question 52

Which of the following processes produces the most ATP per molecule of glucose oxidized?

A) aerobic respiration
B) alcoholic fermentation
C) lactic acid fermentation

Question 53

In yeast cells

A) lactic acid is produced during anaerobic respiration.
B) lactic acid is produced during glycolysis.
C) alcohol is produced during the citric acid cycle.
D) alcohol is produced after glycolysis.

Question 54

Which of the following statements about the energy yield of aerobic respiration is false?

A) Most of the ATP derived during aerobic respiration results from oxidative phosphorylation.
B) Oxidative phosphorylation resulting from 1 glucose molecule yields about 12 ATP molecules.
C) The total yield of ATP molecules per glucose molecule is about 32.

Question 55

The conversion of CO2 and H2O into organic compounds using energy from light is called

A) glycolysis.
B) photosynthesis.
C) fermentation.
D) cellular respiration.

Question 56

Some friends are trying to make wine in their basement. They've added yeast to a sweet grape juice mixture and have allowed the yeast to grow. After several days they find that sugar levels in the grape juice have dropped, but there's no alcohol in the mixture. The most likely explanation is that the

A) mixture needs more sugar because yeasts need a lot of energy before they can begin to produce alcohol.
B) mixture needs less oxygen because yeasts only produce alcohol in the absence of oxygen.
C) mixture needs more oxygen because yeasts need oxygen to break down sugar and get enough energy to produce alcohol.
D) yeast used the alcohol as a carbon source.

Question 57

If you consume 1 g of each of the following, which will yield the most ATP?

A) fat
B) glucose
C) protein
D) starch

Question 58

When a cell uses fatty acids for aerobic respiration, it first hydrolyzes fats to

A) glycerol and amino acids.
B) glycerol and fatty acids.
C) fatty acids and sugars.
D) sugars and glycerol.

Question 59

If ATP accumulates in a cell

A) the cell receives a signal that there is a need for more energy.
B) feedback inhibition speeds up cellular respiration.
C) feedback inhibition slows down cellular respiration.
D) the rate of cellular respiration does not change.

Question 60

In fermentation, ________ is ________.

A) NADH; reduced
B) NAD+; oxidized
C) NADH; oxidized
D) ethanol; oxidized

Question 61

Which step of the citric acid cycle requires both NAD+ and ADP as reactants?

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

Question 62

The antibiotic oligomycin works by inhibiting ATP synthase. You would expect that

A) there will be an increase in ATP production.
B) H+ will accumulate in the intermembrane space.
C) H+ will accumulate in the mitochondrial matrix.
D) NAD+ and FAD will pick up the extra H+.

Question 63

After reading the paragraph below, answer the questions that follow.
Most bats are inactive during the day (this is known as torpor) and feed during the night. The graph below shows hypothetical data for a bat species.

Why does the relationship between metabolic rate and temperature exist?

A) Cellular respiration requires organisms to take in heat energy.
B) A by-product of cellular respiration is heat.
C) Cellular respiration causes the body to cool because all the energy is used to make ATP.

Question 64

The Pasteur effect shows that yeasts consume glucose at a higher rate under anaerobic conditions than under aerobic conditions. Which of the following statements correctly explains this observation?

A) Yeasts are obligate anaerobes, so aerobic conditions will kill yeasts.
B) Yeasts are photosynthetic, so they are able to produce their own oxygen.
C) Less ATP is made under anaerobic conditions, so more glucose must be consumed to produce an equivalent amount of ATP.

Question 65

Wood frogs freeze solid during the winter and then thaw in the spring. As the freezing progresses, blood circulation stops. How would you expect cells not being served by the circulatory system to produce ATP during this time, and what by-product would you expect to build up in the cells?

A) aerobic respiration and CO2
B) fermentation and lactate
C) fermentation and alcohol
D) photosynthesis and O2

Question 66

Arsenic is a poison that binds to a molecule needed to build acetyl CoA. Based on this information, which part of cellular respiration would be stopped if arsenic were ingested?

A) glycolysis
B) citric acid cycle
C) electron transport chain
D) ATP synthase

Question 67

Which of the following statements about the energy yield of aerobic respiration is false?

A) Glycolysis resulting from 1 glucose molecule yields 2 ATP molecules.
B) The oxidation of pyruvate results in the production of 0 ATP molecules.
C) Oxidative phosphorylation resulting from 1 glucose molecule yields 12 ATP molecules.
D) The citric acid cycle resulting from 1 glucose molecules yields 2 ATP molecules.

Question 68

Cellular respiration demonstrates the theme of matter and energy in that

A) matter in food is turned into energy in ATP.
B) energy in food is transferred to energy in ATP.
C) matter in ATP is used to fuel biosynthesis.
D) energy in food becomes matter in forming new molecules.

Question 69

Food provides

A) raw materials for biosynthesis only.
B) energy for cell activities only.
C) raw materials for biosynthesis and energy for cell activities.

Question 70

After reading the paragraph below, answer the questions that follow.
As a scientist employed by the FDA, you've been asked to sit on a panel to evaluate a pharmaceutical company's application for approval of a new weight loss drug called Fat Away. The company has submitted a report summarizing the results of their animal and human testing. In the report, it was noted that Fat Away works by affecting the electron transport chain. It decreases the synthesis of ATP by making the mitochondrial membrane permeable to H+, which allows H+ to leak from the intermembrane space to the mitochondrial matrix. This effect leads to weight loss.
You predict that a side effect of Fat Away will be increased

A) production of NADH.
B) production of pyruvate.
C) production of lactate.
D) body temperature.

Question 71

NADH pills can be purchased over the counter and are often taken by sufferers of chronic fatigue syndrome (CFS). What is the hypothesis about how these pills might benefit a CFS patient?

A) They would increase energy by creating more FADH2.
B) They would decrease the rate of glycolysis.
C) They would increase the number of electrons provided to the electron transport chain.
D) They would decrease the rate of alcoholic fermentation.

Question 72

People who have phenylketonuria, a genetic disorder, are unable to break down the amino acid phenylalanine so that it can be used in cellular respiration. Yet they need phenylalanine in their diet. Why do they need to eat some foods with phenylalanine?

A) Amino acids yield the most energy per gram, so they need phenylalanine to supply their cells with energy.
B) Amino acids are used to build proteins and so they need enough phenylalanine for biosynthesis without any leftover that needs to be broken down to enter cellular respiration.
C) Cellular respiration can use proteins more readily than other types of molecules, so the amino acid phenylalanine is essential.

Question 73

After reading the paragraph below, answer the questions that follow.
Most bats are inactive during the day (this is known as torpor) and feed during the night. The graph below shows hypothetical data for a bat species.

Based on this graph, what is the relationship between metabolic rate and body temperature?

A) When metabolic rate drops, so does body temperature.
B) When metabolic rate drops, body temperature rises.
C) When metabolic rate drops, body temperature remains constant.

Question 74

After reading the paragraph below, answer the questions that follow.
As a scientist employed by the FDA, you've been asked to sit on a panel to evaluate a pharmaceutical company's application for approval of a new weight loss drug called Fat Away. The company has submitted a report summarizing the results of their animal and human testing. In the report, it was noted that Fat Away works by affecting the electron transport chain. It decreases the synthesis of ATP by making the mitochondrial membrane permeable to H+, which allows H+ to leak from the intermembrane space to the mitochondrial matrix. This effect leads to weight loss.
Fat Away prevents ATP from being made by

A) eliminating the H+ gradient that allows ATP synthase to work.
B) preventing glycolysis from occurring.
C) preventing the conversion of NADH to NAD+.
D) slowing down the citric acid cycle.

Question 75

NADH is also used by cells when making certain molecules. Based on your knowledge of the role of NADH in cellular respiration, what do you think NADH's role is in biosynthesis of molecules?

A) oxidizing molecules
B) reducing molecules
C) phosphorylating molecules
D) dehydrating molecules

Question 76

DNP is a chemical that has been used by people to lose weight. However, it is a dangerous option and has caused several people to die. DNP works in a fashion similar to that of brown fat. Based on this information, how would DNP cause weight loss and death?

A) DNP must prevent food from being consumed aerobically, so cells instead perform fermentation, and lactate buildup is deadly.
B) DNP must increase the rate of substrate-level phosphorylation, causing NADH to be produced more quickly than it can be used by the electron transport chain.
C) DNP must block cells from using fats and proteins to make ATP.
D) DNP must increase metabolism of food by producing heat instead of ATP.

Question 77

After reading the paragraph below, answer the questions that follow.
Most bats are inactive during the day (this is known as torpor) and feed during the night. The graph below shows hypothetical data for a bat species.

Bats contain brown fat between their shoulder blades. How could this brown fat be an adaptation to torpor?

A) Brown fat has many mitochondria, so it can produce more ATP.
B) Brown fat can produce heat and ATP through fermentation.
C) The mitochondria in brown fat can produce heat without making ATP.
D) It is not an adaptation; white fat is what they need to produce heat.

Question 78

Which H+ has just passed through the inner mitochondrial membrane by facilitated diffusion?

A) hydrogen ion A
B) hydrogen ion B
C) hydrogen ion C
D) hydrogen ion D

Question 79

A friend tells you that he is going on a low-carb diet to lose weight because he thinks that carbs contain more energy than fats or protein. What would you tell your friend about his plan?

A) This is a good idea because sugars enter the fuel breakdown pathway earlier than other food molecules.
B) This is a good idea because sugars have more electrons than fats and protein.
C) This is a bad idea because fats contain more hydrogen atoms than carbohydrates and protein.
D) This is a bad idea because all food molecules store the same amount of energy.

Question 80

Marathon runners are long-distance runners (marathons are races that are 26.2 miles long). Studies have shown that the muscles of marathon runners contain an abundance of slow-twitch muscle cells. Which of the following statements about these fibers is true?

A) Slow-twitch fibers have lots of mitochondria to make ATP aerobically.
B) Slow-twitch fibers have lots of mitochondria to make ATP through fermentation.
C) Slow-twitch fibers have few mitochondria and make ATP aerobically.
D) Slow-twitch fibers have few mitochondria and make ATP through fermentation.