Chapter 7 How Cells Harvest Energy Flashcards
Chapter 7
Select the groups of organisms that are autotrophs.
Multiple select question.
animals
all bacteria
algae
plants
algae
plants
Unlike heterotrophs, many autotrophs can use energy from what source to synthesize organic compounds?
Multiple choice question.
Nitrogen gas
Water
Sunlight
Infrared heat
Sunlight
The process by which eukaryotic cells harvest energy from organic compounds is termed
____ ______
cellular respiration
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.
Many molecules in food can be used as energy sources, including proteins, carbohydrates, and fats.
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.
Large molecules are broken into smaller ones.
In terms of the source of their carbon, plants are
____
, and animals are
____
autotrophs, heterotrophs
The reactions of energy metabolism, in which energy is harvested from organic molecules, are Blank______ reactions.
Multiple choice question.
hydrolysis
oxidation
reduction
hydrogenation
oxidation
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.
Both autotrophs and heterotrophs can extract energy from organic compounds.
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
A means to extract energy from organic molecules
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
carbohydrates
proteins
fats
Energy is extracted from food molecules using enzyme-catalyzed Blank______ reactions that convert the energy to ATP.
Multiple choice question.
photosynthetic
buffering
redox
transcription
redox
The final electron acceptor in aerobic respiration is which of the following?
Multiple choice question.
ATP
Carbon dioxide
Water
Oxygen
Oxygen
Dehydrogenations are reactions in which lost electrons are accompanied by which of the following?
Multiple choice question.
Enzymes
Nucleotides
Water
Protons
Protons
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.
They can be reversibly oxidized and reduced.
When an atom accepts an electron it is said to be which of the following?
Multiple choice question.
Catalyzed
Oxidized
Reduced
Reduced
When NAD+
is reduced it becomes Blank______.
Multiple choice question.
NADH
NADH2
NAD
NAD-
NADH
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 ____
fermentation
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
A little at a time, so that more of the useful energy can be used to produce ATP
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
Soluble carriers
Membrane-bound carriers that form a redox chain
Carriers that move within the membrane
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).
2 and 1
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
The citric acid cycle
Glycolysis
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
Inner membrane of the mitochondria
Reduced form of nicotinamide adenine dinucleotide ___
NADH
___ is the molecule that powers most of the cell’s activities that require energy.
ATP
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.
When energy is released a little at a time, cells can recover more energy in a useful form.
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.
substrate and oxidative
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
substrate-level phosphorylation
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
electron carriers
The electron carriers of the electron transport chain of eukaryotic cells are located in the inner membrane of the
____
mitochondria
When ATP is synthesized by the enzyme ATP synthase, which of the following is occurring?
Multiple choice question.
Fermentation
Oxidative phosphorylation
Substrate-level phosphorylation
Oxidative phosphorylation
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
Inner mitochondrial membrane
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
Oxidative phosphorylation
Substrate-level phosphorylation
During glycolysis, one molecule of
____ is broken down into two molecules of pyruvate, driving the synthesis of ATP.
GLUCOSE
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.
Two ATPs are used to convert a glucose molecule to 2 G3P molecules.
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
Oxidative phosphorylation
Glycolysis results in a net gain of
____ ATP per glucose molecule.
2
Removal of a phosphate from phosphoenolpyruvate (PEP) creates pyruvate and ___
ATP
Select molecules that are produced during the second half (last 5 steps) of glycolysis.
Multiple select question.
ADP
G3P
ATP
glucose
pyruvate
ATP
pyruvate
How many ATP molecules are consumed during the priming reactions of glycolysis for one molecule of glucose?
Multiple choice question.
8
32
4
2
2
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
two 3-carbon monophosphate sugars
Which of the following processes can occur without oxygen being present?
Multiple choice question.
Electron transport chain
Glycolysis
Citric acid cycle
Glycolysis
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
ATP
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.
Electrons are transferred to oxygen and water is formed.
NADH must be oxidized to
____ in order for glycolysis to continue.
NAD+
Which of the following molecules is generated during the oxidation phase of glycolysis?
Multiple choice question.
FADH2
NADH
correct
G3P
ADP
NADH
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.
Glucose is converted to 2 molecules of pyruvate.
ADP is converted to ATP via substrate level phosphorylation.
NAD+ is reduced to NADH.
During the oxidation of pyruvate, which molecule is reduced?
Multiple choice question.
NAD+
Glucose
Oxygen
NADH
NAD+
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
Aerobic respiration
Fermentation
- Oxidation of pyruvate is both dehydrogenation and ____ reactions
decarboxylation
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
CO2 is removed from pyruvate
NAD+ is reduced
An acetyl group is attached to coenzyme A (CoA)
During fermentation, most of the pyruvate produced during glycolysis is used to convert NADH to ____
NAD+
What molecule enters the citric acid cycle and combines with oxaloacetate to form citric acid?
Multiple choice question.
Glucose
NADH
Malic acid
Acetyl-CoA
Acetyl-CoA
Which of the following are produced when pyruvate is oxidized?
Multiple select question.
Carbon dioxide
G3P
ATP
A 2-carbon compound
NADH
Carbon dioxide
A 2-carbon compound
NADH
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+
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1 FADH2
1 ATP
3 NADH
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.
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.
___- COA enters kreb cycle and combines with oxaloacetate to form ___ acid
acetyl and citric
The complex of enzymes that removes CO2 from pyruvate is called pyruvate Blank______.
Multiple choice question.
oxidase
dehydrogenase
synthase
dehydrogenase
During the oxidation of pyruvate, which molecule is reduced?
Multiple choice question.
Oxygen
Glucose
NADH
NAD+
NAD+
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
ye
In the process of aerobic respiration, what molecule is entirely consumed?
Multiple choice question.
NADH
ATP
Acetyl-CoA
Glucose
Glucose
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
down an energy gradient
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
succinate
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
succinyl-CoA
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
Ubiquinone
Cytochrome c
Select the products yielded by the passage of glucose through glycolysis and the citric acid cycle.
Multiple select question.
NAD+
NADH
ATP
CO2
NADH
ATP
CO2
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
Less energy than those of NADH
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
the electron transport chain; oxygen
When electrons reach the end of the electron transport chain in mitochondria, the final electron acceptor is
_____
oxygen
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
3 NADH
1 ATP
1 FADH2
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
three; two
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.
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.
The mitochondrial matrix has what charge compared with the intermembrane space?
Multiple choice question.
Negative
They are the same.
Positive
Negative
Complexes in Electron Transport Chain Ranked
Start to Last
NADH dehydrogenase
bc1 complex
cytochrome oxidase complex
ye
During the process of
____energy stored in a proton gradient is used to synthesize ATP from ADP and Pi.
chemiosmosis
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
NADH donates to NADH dehydrogenase; FADH2 donates to ubiquinone
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.
shape
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
F0 complex and stalk; F1 complex
The two electrons in Blank______ can be used to synthesize 2.5 ATPs in the ETC.
Multiple choice question.
NADH
FADH
glucose
NADH
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
It is lower
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
32; 30
Which of the following parts of ATP synthase is composed of the stalk and a knob?
Multiple choice question.
F1
F0
Rotor
F1
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%
32%
During aerobic respiration in mitochondria, the yield of ATP is lowered, because ____
produced in the cytoplasm has to be actively transported into the mitochondrion.
NADH
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.
High levels of ATP inhibit phosphofructokinase, while high levels of ADP activate it.
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
Protons required for rotation
Which of the following parts of ATP synthase is composed of the stalk and a knob?
Multiple choice question.
F0
F1
Rotor
F1
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
Nitrate
Sulfur
CO2
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.
10 and 6
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
From organic molecules produced by other organisms
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
H2S
When ATP is in excess in cells, acetyl-CoA is used to produce
______ _____________
fatty acids
What do methanogens use as their electron acceptor for anaerobic respiration?
Multiple choice question.
Nitrate
Oxygen
CO2
Sulfur
CO2
In the absence of oxygen, electrons generated by glycolysis can be donated to organic molecules to recycle NAD+ in a process called
_____
fermentation
Breads made with yeast rise due to the release of
___ ________ produced during ethanol fermentation.
carbon dioxide
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
photosynthesis
The accumulation of
____ _______
in muscle cells as a byproduct of fermentation when oxygen is not available, can lead to muscle fatigue.
lactic acid
When a cell needs ATP, fatty acids are degraded to provide
___ - _____
for the citric acid cycle.
acetyl-CoA
