Chapter 7 How Cells Harvest Energy

Question 1

Select the groups of organisms that are autotrophs.

Multiple select question.

animals

all bacteria

algae

plants

Answer 1

algae

plants

Question 2

Unlike heterotrophs, many autotrophs can use energy from what source to synthesize organic compounds?

Multiple choice question.

Nitrogen gas

Water

Sunlight

Infrared heat

Answer 2

Sunlight

Question 3

The process by which eukaryotic cells harvest energy from organic compounds is termed
____ ______

Answer 3

cellular respiration

Question 4

Which statement accurately lists the types of molecules in food that can be used by cells as energy sources?

Multiple choice question.

Only simple carbohydrates, such as glucose, can be used as energy sources.

Only carbohydrates (simple or complex) and fats can be used as energy source.

Only carbohydrates (simple, or complex) can be used as energy sources.

Many molecules in food can be used as energy sources, including proteins, carbohydrates, and fats.

Answer 4

Many molecules in food can be used as energy sources, including proteins, carbohydrates, and fats.

Question 5

What occurs during food digestion?

Multiple choice question.

Energy in large molecules is used to make ATP.

Energy from ATP is used to prepare large molecules for cellular respiration.

Small molecules are combined into larger ones.

Large molecules are broken into smaller ones.

Answer 5

Large molecules are broken into smaller ones.

Question 6

In terms of the source of their carbon, plants are
____
, and animals are
____

Answer 6

autotrophs, heterotrophs

Question 7

The reactions of energy metabolism, in which energy is harvested from organic molecules, are Blank______ reactions.

Multiple choice question.

hydrolysis

oxidation

reduction

hydrogenation

Answer 7

oxidation

Question 8

Which statement accurately compares the ability of heterotrophs and autotrophs to extract energy from organic compounds?

Multiple choice question.

Only autotrophs can extract energy from organic compounds.

Only heterotrophs can extract energy from organic compounds.

Both autotrophs and heterotrophs can extract energy from organic compounds.

Answer 8

Both autotrophs and heterotrophs can extract energy from organic compounds.

Question 9

Which of the following is the best description of the process of cellular respiration?

Multiple choice question.

A means to extract energy from oxygen

A means to extract energy from inorganic molecules

A means to utilize ATP in cells

A means to extract energy from organic molecules

Answer 9

A means to extract energy from organic molecules

Question 10

Which of the following molecules in food can be used as energy sources by living organisms?

Multiple select question.

water

molecular oxygen

carbohydrates

proteins

fats

Answer 10

carbohydrates

proteins

fats

Question 11

Energy is extracted from food molecules using enzyme-catalyzed Blank______ reactions that convert the energy to ATP.

Multiple choice question.

photosynthetic

buffering

redox

transcription

Answer 11

redox

Question 12

The final electron acceptor in aerobic respiration is which of the following?

Multiple choice question.

ATP

Carbon dioxide

Water

Oxygen

Answer 12

Oxygen

Question 13

Dehydrogenations are reactions in which lost electrons are accompanied by which of the following?

Multiple choice question.

Enzymes

Nucleotides

Water

Protons

Answer 13

Protons

Question 14

Which of the following is a common feature of all electron carriers used during cellular respiration?

Multiple choice question.

They can be reversibly oxidized and reduced.

They are membrane-bound.

They can remove electrons from oxygen.

They can carry both protons and electrons.

Answer 14

They can be reversibly oxidized and reduced.

Question 15

When an atom accepts an electron it is said to be which of the following?

Multiple choice question.

Catalyzed

Oxidized

Reduced

Answer 15

Reduced

Question 16

When NAD+
is reduced it becomes Blank______.

Multiple choice question.

NADH

NADH2

NAD

NAD-

Answer 16

NADH

Question 17

After energy from food molecules has been extracted to make ATP, electrons are transferred to a final acceptor. When the final electron acceptor is an organic molecule, the process is termed ____

Answer 17

fermentation

Question 18

How do cells oxidize their glucose?

Multiple choice question.

All at once, so that as much of the useful energy as possible can be used to produce ATP

All at once, so that less energy is lost as heat

A little at a time, so that all of the chemical energy can be used to produce ATP

A little at a time, so that more of the useful energy can be used to produce ATP

Answer 18

A little at a time, so that more of the useful energy can be used to produce ATP

Question 19

Select all of the following that can be electron carriers.

Multiple select question.

Soluble carriers

Molecules that are irreversibly oxidized and reduced

Membrane-bound carriers that form a redox chain

Carriers that move within the membrane

Answer 19

Soluble carriers

Membrane-bound carriers that form a redox chain

Carriers that move within the membrane

Question 20

To receive credit for this question, you must fill the blanks with numbers (for example, 3). When NAD+ is reduced, it accepts
___ electron(s) and
____ proton(s).

Answer 20

2 and 1

Question 21

Select the processes that are used by cells to strip electrons off of the C-H
bonds of a glucose molecule.

Multiple select question.

Chemiosmosis

The citric acid cycle

Glycolysis

Substrate-level phosphorylation

Answer 21

The citric acid cycle

Glycolysis

Question 22

In a eukaryotic cell, where are the electron carriers of the electron transport chain located?

Multiple choice question.

Outer membrane of the mitochondria

Plasma membrane

Nuclear membrane

Inner membrane of the mitochondria

Answer 22

Inner membrane of the mitochondria

Question 23

Reduced form of nicotinamide adenine dinucleotide ___

Answer 23

NADH

Question 24

___ is the molecule that powers most of the cell’s activities that require energy.

Answer 24

ATP

Question 25

During the breakdown of glucose, why is it beneficial to release energy a little at a time rather than all at once? Multiple choice question. When energy is released a little at a time, fewer enzymes are required to catalyze the process. When energy is released a little at a time, less ATP is used. When energy is released a little at a time, more energy is burned off as heat. When energy is released a little at a time, cells can recover more energy in a useful form.

Answer 25

When energy is released a little at a time, cells can recover more energy in a useful form.

Question 26

Question Mode Fill in the Blank Question Fill in the blank question. The two mechanisms used by eukaryotes to synthesize most of their ATP are ____ -level phosphorylation and ___ phosphorylation.

Answer 26

substrate and oxidative

Question 27

The transfer of a high energy phosphate group from a phosphorylated organic molecule to ADP is referred to as Blank______. Multiple choice question. reductive phosphorylation oxidative phosphorylation substrate-level phosphorylation chemiosmotic phosphorylation

Answer 27

substrate-level phosphorylation

Question 28

Electrons that are removed from the C—H bonds of glucose during glycolysis and the Krebs cycle are donated to Blank______. Multiple choice question. ATP molecules electron carriers oxygen ADP molecules

Answer 28

electron carriers

Question 29

The electron carriers of the electron transport chain of eukaryotic cells are located in the inner membrane of the ____

Answer 29

mitochondria

Question 30

When ATP is synthesized by the enzyme ATP synthase, which of the following is occurring? Multiple choice question. Fermentation Oxidative phosphorylation Substrate-level phosphorylation

Answer 30

Oxidative phosphorylation

Question 31

The electron transport chain in humans is located in which of the following parts of the cell? Multiple choice question. Plasma membrane Outer mitochondrial membrane Cytoplasm Inner mitochondrial membrane

Answer 31

Inner mitochondrial membrane

Question 32

Select the two mechanisms that eukaryotic cells use to synthesize the majority of their ATP. Multiple select question. Oxidative phosphorylation Fermentative phosphorylation Substrate-level phosphorylation Non-oxidative phosphorylation

Answer 32

Oxidative phosphorylation Substrate-level phosphorylation

Question 33

During glycolysis, one molecule of ____ is broken down into two molecules of pyruvate, driving the synthesis of ATP.

Answer 33

GLUCOSE

Question 34

What happens during the first half of glycolysis? Multiple choice question. A glucose molecule is converted to 2 G3P molecules and 2 ATPs are made. incorrect A glucose molecule is converted to 2 ATP molecules. A glucose molecule is converted to 2 molecules of pyruvate and 2 ATPs are made. Two ATPs are used to convert a glucose molecule to 2 G3P molecules.

Answer 34

Two ATPs are used to convert a glucose molecule to 2 G3P molecules.

Question 35

The ATP produced as a result of the proton gradient established by the electron transport chain is the result of which of the following? Multiple choice question. Substrate-level phosphorylation Oxidative phosphorylation Fermentation

Answer 35

Oxidative phosphorylation

Question 36

Glycolysis results in a net gain of ____ ATP per glucose molecule.

Answer 36

2

Question 37

Removal of a phosphate from phosphoenolpyruvate (PEP) creates pyruvate and ___

Answer 37

ATP

Question 38

Select molecules that are produced during the second half (last 5 steps) of glycolysis. Multiple select question. ADP G3P ATP glucose pyruvate

Answer 38

ATP pyruvate

Question 39

How many ATP molecules are consumed during the priming reactions of glycolysis for one molecule of glucose? Multiple choice question. 8 32 4 2

Answer 39

2

Question 40

At the end of the first stage of glycolysis, a 6-carbon diphosphate sugar is split into Blank______. Multiple choice question. two 3-carbon diphosphate sugars two 2-carbon diphosphate sugars one 4-carbon diphosphate sugar and one 2-carbon sugar two 3-carbon monophosphate sugars

Answer 40

two 3-carbon monophosphate sugars

Question 41

Which of the following processes can occur without oxygen being present? Multiple choice question. Electron transport chain Glycolysis Citric acid cycle

Answer 41

Glycolysis

Question 42

During glycolysis, when a phosphate group is removed from 1,3-bisphosphoglycerate to create 3-phosphoglycerate, what else is produced? Multiple choice question. Water NADH NAD+ Pyruvate ATP

Answer 42

ATP

Question 43

Which of the following does not occur during glycolysis? Multiple choice question. NAD+ is reduced to NADH. Glucose is converted to two molecules of pyruvate. Electrons are transferred to oxygen and water is formed. Substrate-level phosphorylation of ADP occurs.

Answer 43

Electrons are transferred to oxygen and water is formed.

Question 44

NADH must be oxidized to ____ in order for glycolysis to continue.

Answer 44

NAD+

Question 45

Which of the following molecules is generated during the oxidation phase of glycolysis? Multiple choice question. FADH2 NADH correct G3P ADP

Answer 45

NADH

Question 46

Select the main changes that occur during glycolysis. Multiple select question. Glucose is converted to 2 molecules of pyruvate. Glucose is formed. NADH is oxidized to NAD+. ADP is converted to ATP via substrate level phosphorylation. NAD+ is reduced to NADH.

Answer 46

Glucose is converted to 2 molecules of pyruvate. ADP is converted to ATP via substrate level phosphorylation. NAD+ is reduced to NADH.

Question 47

During the oxidation of pyruvate, which molecule is reduced? Multiple choice question. NAD+ Glucose Oxygen NADH

Answer 47

NAD+

Question 48

What are the two ways in which a eukaryotic cell can regenerate NAD+ needed to continue carrying out glycolysis? Multiple select question. Reverse glycolysis Aerobic respiration Fermentation Substrate-level phosphorylation

Answer 48

Aerobic respiration Fermentation

Question 49

- Oxidation of pyruvate is both dehydrogenation and ____ reactions

Answer 49

decarboxylation

Question 50

Select the events that occur in the reaction that produces acetyl-CoA. Multiple select question. CO2 is removed from pyruvate NAD+ is reduced An acetyl group is attached to coenzyme A (CoA) FADH2 is oxidized

Answer 50

CO2 is removed from pyruvate NAD+ is reduced An acetyl group is attached to coenzyme A (CoA)

Question 51

During fermentation, most of the pyruvate produced during glycolysis is used to convert NADH to ____

Answer 51

NAD+

Question 52

What molecule enters the citric acid cycle and combines with oxaloacetate to form citric acid? Multiple choice question. Glucose NADH Malic acid Acetyl-CoA

Answer 52

Acetyl-CoA

Question 52

Which of the following are produced when pyruvate is oxidized? Multiple select question. Carbon dioxide G3P ATP A 2-carbon compound NADH

Answer 52

Carbon dioxide A 2-carbon compound NADH

Question 53

Question Mode Multiple Select Question Select all that apply Select all of the following that are produced with 1 turn of the citric acid cycle. Multiple select question. 1 FADH2 1 ATP 3 NADH 1 pyruvate 3 NAD+ Need help? Review these concept resources

Answer 53

1 FADH2 1 ATP 3 NADH

Question 54

Select all of the following that are true statements describing one round of the Krebs cycle. Multiple select question. Four pairs of electrons are removed from four of the intermediates in the cycle. Two oxygen molecules are produced. Four CO2 molecules are released from four of the intermediates in the cycle. A 2-carbon group from acetyl-CoA enters the cycle. One molecule of ATP is produced.

Answer 54

Four pairs of electrons are removed from four of the intermediates in the cycle. A 2-carbon group from acetyl-CoA enters the cycle. One molecule of ATP is produced.

Question 54

___- COA enters kreb cycle and combines with oxaloacetate to form ___ acid

Answer 54

acetyl and citric

Question 55

The complex of enzymes that removes CO2 from pyruvate is called pyruvate Blank______. Multiple choice question. oxidase dehydrogenase synthase

Answer 55

dehydrogenase

Question 55

During the oxidation of pyruvate, which molecule is reduced? Multiple choice question. Oxygen Glucose NADH NAD+

Answer 55

NAD+

Question 56

Citric Acid Cycle 1. Isomerization - attachment of an acetyl group to oxaloacetate 2. First oxidation 3. Second Oxidation 4. Substrate Level Phosphorylation 5. Third oxidation 6. Regeneration of Oxaloacetate

Answer 56

ye

Question 57

In the process of aerobic respiration, what molecule is entirely consumed? Multiple choice question. NADH ATP Acetyl-CoA Glucose

Answer 57

Glucose

Question 58

During each step of the electron transport system, electrons move to a more electronegative carrier, and thus move Blank______. Multiple choice question. up an energy gradient to higher and higher energy levels down an energy gradient alternately between lower and higher energy levels

Answer 58

down an energy gradient

Question 59

In the citric acid cycle, citrate undergoes five steps during which it is oxidized and decarboxylated to produce the four carbon molecule Blank______. Multiple choice question. oxaloacetate G3P pyruvate succinate

Answer 59

succinate

Question 60

During the citric acid cycle, a molecule of ATP is formed through substrate-level phosphorylation, using a high energy bond in Blank______. Multiple choice question. succinyl-CoA acetyl-CoA citrate malate

Answer 60

succinyl-CoA

Question 61

Select the carrier molecules that move electrons from complex to complex in the electron transport chain. Multiple select question. NADH dehydrogenase Ubiquinone bc1 complex Cytochrome c

Answer 61

Ubiquinone Cytochrome c

Question 62

Select the products yielded by the passage of glucose through glycolysis and the citric acid cycle. Multiple select question. NAD+ NADH ATP CO2

Answer 62

NADH ATP CO2

Question 63

In the electron transport chain, the electrons from FADH2 release which of the following? Multiple choice question. As much energy as those of NADH More energy than those of NADH Less energy than those of NADH

Answer 63

Less energy than those of NADH

Question 64

During aerobic respiration, NADH delivers electrons to Blank______, and then Blank______ captures electrons at the end and joins with hydrogen to form water. Multiple choice question. the electron transport chain; FAD the citric acid cycle; oxygen the electron transport chain; oxygen the citric acid cycle; FAD

Answer 64

the electron transport chain; oxygen

Question 65

When electrons reach the end of the electron transport chain in mitochondria, the final electron acceptor is _____

Answer 65

oxygen

Question 66

Select all of the following that are produced with 1 turn of the citric acid cycle. Multiple select question. 3 NADH 1 ATP 1 pyruvate 3 NAD+ 1 FADH2

Answer 66

3 NADH 1 ATP 1 FADH2

Question 67

The electrons donated to the electron transport chain by NADH activate Blank______ proton pumps, while those donated by FADH2 activate Blank______ proton pumps. Multiple choice question. two; three three; one three; two one; three

Answer 67

three; two

Question 68

Select all of the following that are true statements describing one round of the Krebs cycle. Multiple select question. Two oxygen molecules are produced. A 2-carbon group from acetyl-CoA enters the cycle. Four CO2 molecules are released from four of the intermediates in the cycle. One molecule of ATP is produced. Four pairs of electrons are removed from four of the intermediates in the cycle.

Answer 68

A 2-carbon group from acetyl-CoA enters the cycle. One molecule of ATP is produced. Four pairs of electrons are removed from four of the intermediates in the cycle.

Question 69

The mitochondrial matrix has what charge compared with the intermembrane space? Multiple choice question. Negative They are the same. Positive

Answer 69

Negative

Question 70

Complexes in Electron Transport Chain Ranked Start to Last NADH dehydrogenase bc1 complex cytochrome oxidase complex

Answer 70

ye

Question 71

During the process of ____energy stored in a proton gradient is used to synthesize ATP from ADP and Pi.

Answer 71

chemiosmosis

Question 72

In the electron transport chain, how do NADH and FADH2 donate their electrons? Multiple choice question. Both NADH and FAH2 donate to ubiquinone NADH donates to NADH dehydrogenase; FADH2 donates to ubiquinone NADH donates to ubiquinone; FADH2 donates directly to O2 incorrect NADH donates to NADH dehydrogenase; FADH2 donates to the cytochrome oxidase complex

Answer 72

NADH donates to NADH dehydrogenase; FADH2 donates to ubiquinone

Question 73

The flow of highly energetic electrons through the electron transport chain changes the ____ of the pump proteins, which causes them to transport protons across the membrane.

Answer 73

shape

Question 74

During formation of ATP by ATP synthase, rotation of the Blank______ causes a conformational change in the Blank______, which has the enzymatic activity. Multiple choice question. F0 complex and stalk; F1 complex F1 complex; F0 complex stalk and F1 complex; F0 complex catalytic head; stalk

Answer 74

F0 complex and stalk; F1 complex

Question 75

The two electrons in Blank______ can be used to synthesize 2.5 ATPs in the ETC. Multiple choice question. NADH FADH glucose

Answer 75

NADH

Question 76

How does the actual yield of ATP compare to the theoretical yield of ATP during aerobic respiration in mitochondria? Multiple choice question. It is the same It is higher It is lower

Answer 76

It is lower

Question 77

The actual number of ATP molecules generated per one molecule of glucose by aerobic respiration is Blank______ in prokaryotes and Blank______ in eukaryotes. Multiple choice question. 30; 32 6; 10 10; 6 32; 30

Answer 77

32; 30

Question 78

Which of the following parts of ATP synthase is composed of the stalk and a knob? Multiple choice question. F1 F0 Rotor

Answer 78

F1

Question 79

During aerobic respiration, a eukaryotic cell produces 30 ATPs, each of which can release 7.3 kcal/mol of free energy. Knowing that the free energy released during glucose oxidation is 686 kcal/mol, we can calculate that the efficiency of aerobic respiration is about Blank______. Multiple choice question. 25% 32% 50% 67%

Answer 79

32%

Question 80

During aerobic respiration in mitochondria, the yield of ATP is lowered, because ____ produced in the cytoplasm has to be actively transported into the mitochondrion.

Answer 80

NADH

Question 81

How do ADP and ATP interact with the enzyme phosphofructokinase? Multiple choice question. High levels of ATP inhibit phosphofructokinase, while high levels of ADP activate it. Phosphofructokinase is activated by low levels of either ATP or ADP. High levels of ADP inhibit phosphofructokinase, while high levels of ATP activate it. Phosphofructokinase is inhibited by high levels of either ATP or ADP.

Answer 81

High levels of ATP inhibit phosphofructokinase, while high levels of ADP activate it.

Question 82

The calculation of the P/O ratio depends on the number of binding sites for ATP on ATP synthase and the number of which of the following? Multiple choice question. Protons required for rotation Pi available in the matrix O2 molecules used by ATP synthase Electron binding sites on ATP synthase

Answer 82

Protons required for rotation

Question 83

Which of the following parts of ATP synthase is composed of the stalk and a knob? Multiple choice question. F0 F1 Rotor

Answer 83

F1

Question 84

Select the molecules that many prokaryotes are able to use as final electron acceptors during anaerobic respiration. Multiple select question. Nitrate Acetic acid Alcohol Sulfur CO2

Answer 84

Nitrate Sulfur CO2

Question 85

The P/O ratio takes into account the fact that, in the electron transport chain, there are protons pumped across the membrane per NADH and protons pumped across the membrane per FADH2.

Answer 85

10 and 6

Question 86

Where do methanogens get the hydrogens involved in reducing CO2 to CH4 in anaerobic respiration? Multiple choice question. From organic molecules that they produce From fermentation From organic molecules produced by other organisms From photosynthesis that they conduct

Answer 86

From organic molecules produced by other organisms

Question 87

In a type of anaerobic respiration called sulfate respiration, prokaryotes derive energy by reducing inorganic sulfates to which of the following compounds? Multiple choice question. SO2 H2S CO2 CH4

Answer 87

H2S

Question 88

When ATP is in excess in cells, acetyl-CoA is used to produce ______ _____________

Answer 88

fatty acids

Question 89

What do methanogens use as their electron acceptor for anaerobic respiration? Multiple choice question. Nitrate Oxygen CO2 Sulfur

Answer 89

CO2

Question 90

In the absence of oxygen, electrons generated by glycolysis can be donated to organic molecules to recycle NAD+ in a process called _____

Answer 90

fermentation

Question 91

Breads made with yeast rise due to the release of ___ ________ produced during ethanol fermentation.

Answer 91

carbon dioxide

Question 92

Early sulfate reducers set the stage for the evolution of Blank______, the first form of which harvested hydrogens from H2S. Multiple choice question. fermentation photosynthesis aerobic respiration

Answer 92

photosynthesis

Question 93

The accumulation of ____ _______ in muscle cells as a byproduct of fermentation when oxygen is not available, can lead to muscle fatigue.

Answer 93

lactic acid

Question 94

When a cell needs ATP, fatty acids are degraded to provide ___ - _____ for the citric acid cycle.

Answer 94

acetyl-CoA