Download electron transport chain

Select the correct sequence of steps as energy is extracted from glucose during cellular
respiration.
acetyl CoA → citric acid cycle → electron transport chain → glycolysis
electron transport chain → citric acid cycle → glycolysis → acetyl CoA
citric acid cycle → electron transport chain → glycolysis → acetyl CoA
glycolysis → citric acid cycle → acetyl CoA → electron transport chain
glycolysis → acetyl CoA → citric acid cycle → electron transport chain
What is the correct general equation for cellular respiration?
C6H12O6 + 6 CO2 6 → O2 + 6 H2O + ATP energy
C6H12O6 + 6 O2 6 → CO2 + 6 H2O + ATP energy
6CO2 + 6 H2O + ATP energy → C6H12O6 + 6 O2
6O2 + 6 H2O + ATP energy → C6H12O6 + 6 CO2
C6H12O6 + 6 H2O 6 → CO2 + 6 O2 + ATP energy
Which of the following processes takes place in the cytosol of a eukaryotic cell?
electron transport chain
ATP production by ATP synthase
acetyl CoA formation
citric acid cycle
glycolysis
In what organelle would you find acetyl CoA formation, the citric acid cycle, and the electron
transport chain?
chloroplast
nucleus
lysosome
mitochondrion
Golgi apparatus
Which statement describes glycolysis?
This process joins 2 pyruvic acid molecules into a molecule of glucose.
This process splits glucose in half and produces 2 ATPs for each glucose.
This process produces some ATP and carbon dioxide in the mitochondrion.
This process uses energy captured from electrons flowing to oxygen to produce most of the
ATPs in cellular respiration.
This process converts pyruvic acid to acetyl CoA.
Which statement describes the citric acid cycle?
This process produces some ATP and carbon dioxide in the mitochondrion.
This process uses energy captured from electrons flowing to oxygen to produce most of the
ATPs in cellular respiration.
This process converts pyruvic acid to acetyl CoA.
This process splits glucose in half and produces 2 ATPs for each glucose.
This process joins 2 pyruvic acid molecules into a molecule of glucose.
Which statement describes the electron transport chain?
This process produces some ATP and carbon dioxide in the mitochondrion.
This process uses energy captured from electrons flowing to oxygen to produce most of the
ATPs in cellular respiration.
This process joins 2 pyruvic acid molecules into a molecule of glucose.
This process converts pyruvic acid to acetyl CoA.
This process splits glucose in half and produces 2 ATPs for each glucose
Sunlight is essential for the varied life on Earth.
Sunlight provides energy to photosynthetic
organisms by providing _____. ( Module 6.1)
heat to leaves, which is
converted to useful energy
for work
heat to leaves, which is used
to synthesize chloroplasts
the energy required to drive
cellular respiration
the energy necessary to
power the rearrangement of
chemical bonds
Lungs are to breathing as _____ are to cellular respiration. (
Module 6.2)
alveoli
bronchi
chloroplasts
mitochondria
When a car engine burns gasoline, the results of the reaction are similar to
when cells burn glucose. Both reactions release carbon dioxide and water. In
cells, the chemical energy in food is converted to ATP and heat. In a moving
car, the chemical energy in gasoline is converted to _____. ( Module 6.3)
kinetic energy and heat
potential energy and heat
thermal energy and heat
ATP and heat
Given the relatively modest number of calories burned by anything but the
most vigorous activities, why can people consume over 2,000 kilocalories a
day, yet maintain a healthy body weight? ( Module 6.4)
They can't, and this has led to a problem of obesity in the United States.
People really should exercise vigorously for one to two hours per day.
Most of the energy consumed in food is spent maintaining the body's
functions, so only a fraction of food energy needs to be burned in
exercise.
Not all calories are created equal, so a person who consumes 2,000
kilocalories of sugar- and fat-laden processed food will gain weight,
while a person who consumes 2,000 calories of nonprocessed, lowcarbohydrate food will not.
A molecule that functions as the electron donor in a redox reaction _____. (
Module 6.5)
gains electrons and gains energy
loses electrons and loses energy
gains electrons and loses energy
loses electrons and gains energy
In cellular respiration, glucose _____ electrons, while _____ electrons. (
Module 6.5)
gains … oxygen loses
loses … oxygen gains
gains … water loses
loses … water gains
Oxidative phosphorylation could not occur without glycolysis and the citric
acid cycle, because _____. ( Module 6.6)
these two stages provide the oxygen used as the final electron acceptor
the electron transport chain requires the ATP produced during the first
two stages
these two stages provide the water that is split during oxidative
phosphorylation
these two stages supply the electrons needed for the electron transport
chain
Glycolysis is the only stage of cellular respiration that _____. (
Module 6.7)
requires ATP to make ATP
does not require ATP to make ATP
requires oxygen to function
does not release carbon dioxide as a by-product
We inhale O2 and we exhale CO2. Carbon dioxide is produced _____. (
Module 6.8)
during the formation of pyruvate
in the reaction that creates acetyl CoA (coenzyme A) from pyruvate
during the electron transfer steps of oxidative phosphorylation
when oxygen acquires electrons and protons at the end of the electron
transport chain
A scientist wants to study the enzymes of the citric acid cycle in eukaryotic
cells. What part of the cell would they use as a source of these enzymes? (
Module 6.9)
plasma membrane
cytoplasm
mitochondrial inner membrane
mitochondrial matrix
What molecule is required to move pyruvate to the citric acid cycle? (
Module 6.9)
NADH
FADH2
ATP
O2
In oxidative phosphorylation, electrons are passed from one electron carrier to
another. The energy released is used to _____. ( Module 6.10)
pump protons (H+) across the mitochondrial membrane
form ATP during glycolysis
synthesize carbon dioxide
generate large amounts of NADH and FADH2
Dinitrophenol (DNP) is a highly toxic, membrane uncoupler. What happens
when DNP makes the phospholipid bilayer of inner mitochondrial membranes
permeable to protons (H+)? ( Module 6.11)
The redox reactions of the electron transport chain cease.
The proton pumps of the inner mitochondrial membrane would cease to
function.
Many protons would bypass ATP synthase, leading to a sharp decline in
ATP synthesis.
NADH or FADH2 would no longer provide electrons to the electron
transport chain.
Some human cells are restricted to aerobic respiration to recycle NADH and
FADH2. If these cells are deprived of oxygen, then _____. ( Module 6.12)
ATP production would continue because the cell would perform
fermentation
proton gradient formation would continue, but ATP synthase function
would stop
glycolysis could still continue indefinitely
oxidative phosphorylation would come to a halt because there wouldn't
be any oxygen to "pull" the electrons down the transport chain
Humans depend on oxygen to sustain life. However, at the cellular level,
muscle cells are _____. ( Module 6.13)
strict anaerobes
facultative anaerobes
aerobes
capable of alcohol fermentation
Fat is the most efficient molecule for long-term energy storage even compared
to carbohydrates because _____. ( Module 6.15)
when compacted, fat occupies less volume than an equivalent amount of
carbohydrate
compared to carbohydrates, fat produces fewer toxic by-products when
it's metabolized
fats can directly enter the electron transport chain, the phase of
respiration that produces the most ATP
with their numerous hydrogen atoms, fats provide an abundant source of
high-energy electrons
Using the ATP generated during
cellular respiration, the
intermediates of glycolysis and
the citric acid cycle can be
siphoned off and used _____. (
Module 6.16)
to generate the ADP that is
used to power biosynthetic
pathways
to power the biosynthesis
of amino acids, fats, and
sugars
to provide virtually all the
heat needed to maintain
body temperature
to create energy sources,
such as glucose or amino
acids, that are recycled
back through respiration,
thus allowing a continual
source of ATP with
relatively little food intake
In preparing
pyruvate to enter
the citric acid
cycle, which of the
following steps
occurs? (
Module 6.8)
Pyruvate is reduced
by oxidizing an
NAD+ to an NADH.
Oxygen atoms are
formed into oxygen
gas.
A compound called
coenzyme A binds
to a two-carbon
fragment.
Carbon dioxide
must be present
for pyruvate to
enter the citric acid
cycle.
The two-carbon
fragment formed
after a carbon
atom is released as
carbon dioxide is
called lactic acid.
When pyruvate is converted to acetyl CoA, _____. (
Module 6.8)
CO2 and ATP are formed
CO2 and NADH are formed
CO2 and coenzyme A are formed
one turn of the citric acid cycle is completed
NAD+ is regenerated
In eukaryotes, most of the high-energy electrons released from glucose by cell
respiration _____. ( Module 6.9)
are used for synthesizing lactic acid
are used to form ATP by the citric acid cycle
are bound to FAD to be sent through the process of oxidative phosphorylation
are released in the carbon dioxide
reduce NAD+ to NADH, which then deliver them to the electron transport
chain
Most of the NADH that delivers high-energy electrons to the electron transport chain
comes from _____. ( Module 6.9)
chemiosmosis
the cytoplasm
glycolysis
biosynthesis
the citric acid cycle
Why is the citric acid cycle called a cycle? (
Module 6.9)
Glucose is cycled around and resynthesized.
NAD+ and FAD are recycled.
Acetyl CoA binds to oxaloacetate that is restored at the end of the cycle.
Carbon dioxide is cycled back to photosynthesis.
NADH is recycled in the electron transport chain.
The energy production per glucose molecule through the citric acid cycle is _____. (
Module 6.9)
2 ATP, 6 NADH, 2 FADH2
38 ATP
4 ATP, 8 NADH
2 ATP, 6 NADH
1 ATP, 3 NADH, 1 FADH2
The major (but not sole) energy
accomplishment of the citric
acid cycle is the _____. (
Module 6.9)
formation of CO2
formation of ATP
formation of NADH and
FADH2
utilization of O2
completion of substratelevel phosphorylation
Once the citric acid cycle has
been completed, most of the
usable energy from the
original glucose molecule is
in the form of _____. (
Module 6.9)
acetyl CoA
ATP
NADH
CO2
oxaloacetate
Which of the following serves primarily as a hydrogen-atom carrier molecule in cells?
( Module 6.9)
ATP
CO2
FAD
RNA
DNA
What happens to the energy that is given up by electrons as they move through the
electron transport chain? ( Module 6.10)
It breaks down glucose.
It makes NADH and FADH2.
It pumps H+ through a membrane.
It oxidizes water.
It manufactures glucose.
The ATP synthase in a human cell gets energy for making ATP directly from _____. (
Module 6.10)
sunlight
the flow of H+ through a membrane
the oxidation of glucose
the movement of electrons through a series of carriers
the reduction of oxygen
What is the mechanism of action for the enzyme ATP synthase? ATP is formed _____.
( Module 6.10)
due to the potential energy of a concentration gradient of hydrogen ions
across a membrane
due to substrate-level phosphorylation
from glucose in the absence of oxygen
in the absence of chemiosmosis
from GTP
In cellular respiration, which
one of the following is
performed directly by the
electron transport chain (or
its components)? ( Module
6.10)
Oxygen gas is formed.
Carbon dioxide is
formed.
ADP is phosphorylated
to make ATP.
FAD is reduced.
A proton gradient is
formed.
The enzyme ATP synthase
catalyzes the
phosphorylation of ADP to
form ATP. In eukaryotic
cells, the energy needed
for this endergonic
reaction is derived from
_____. ( Module 6.10)
DNA replication
the movement of
hydrogen ions
across the
mitochondrial
membrane
the fermentation
of pyruvate to
form lactic acid
the movement of
FADH2 from the
cytoplasm to the
mitochondria
the reduction of
NAD+ to form
NADH
Which one of the following is the source of the energy that produces the
chemiosmotic gradient in mitochondria? ( Module 6.10)
ATP
ATP synthase
cytochrome c
electron transport chain
electrons
In a eukaryotic cell, the electron transport chain is precisely located in or on the
_____. ( Module 6.10)
cytoplasmic fluid
mitochondrion
cristae of the mitochondrion
intermembrane space of the mitochondrion
plasma membrane
Rotenone is a poison that blocks the electron transport chain. When it does so,
glycolysis and the citric acid cycle eventually halt as well. This is because _____. (
Module 6.11)
they run out of ATP
the buildup of unused oxygen interferes with glycolysis and the citric acid
cycle
they run out of NAD+ and FAD
electrons are no longer available from the electron transport chain
they run out of ADP
Carbon monoxide is a toxic gas because it directly _____. (
Module 6.11)
inhibits the oxidation of NADH
blocks the transfer of electrons to the final electron acceptor
inhibits ATP synthase
changes the permeability of the membrane
blocks the delivery of electrons from FADH2
Where does most of the ATP produced in cellular respiration come from? (
Module 6.12)
glycolysis
chemiosmosis
lactic acid fermentation
biosynthesis
the citric acid cycle
Which of the following
directly requires molecular
oxygen (O2)? ( Module
6.12)
glycolysis
the citric acid cycle
the electron transport
chain
fermentation
chemiosmosis
During aerobic
respiration,
molecular oxygen
(O2) is used _____. (
Module 6.12)
at the end of glycolysis
to switch from the
fermentation pathway
at the end of the citric
acid cycle to cycle back
to oxaloacetate
between glycolysis and
the citric acid cycle to
split a carbon from
pyruvate
between the citric acid
cycle and the electron
transport chain to
move NADH and FADH2
at the end of electron
transport chain to
accept electrons and
form H2O
Through respiration, humans breathe in O2 and breathe out CO2. However, what
would happen if we did not breathe in O2? ( Module 6.12)
We would not make enough ATP to meet our energy requirements
We would not have enough enzymes to catalyze reactions.
We would not be able to perform lactic acid fermentation.
We would not be able to synthesize organic molecules from inorganic
molecules.
We would not be affected because we can switch to alcohol fermentation.
A single glucose molecule produces about 38 molecules of ATP through the process
of cellular respiration. However, this only represents approximately 38% of the
chemical energy present in this molecule. The rest of the energy from glucose is
_____. ( Module 6.12)
stored as fat
converted to heat
used to make water from hydrogen ions and oxygen
used directly for energy
stored as starch
The overall efficiency of respiration is approximately _____. (
0.50%
2%
40%
Module 6.12)
94%
100%
In the equation shown below, during cellular respiration _____ is oxidized and _____
is reduced. ( Module 6.12)
oxygen … ATP
ATP … oxygen
glucose … oxygen
carbon dioxide … water
glucose … ATP
Substrate-level phosphorylation directly generates ATP during a chemical reaction.
As a single molecule of glucose is completely oxidized, in the presence of oxygen,
how many molecules of ATP are gained by substrate-level phosphorylation? (
Module 6.12)
2 ATP
4 ATP
6 ATP
36 ATP
38 ATP
Sports physiologists at an Olympic training
center want to monitor athletes to
determine at what point their muscles
begin to function anaerobically. They could
do this by checking for a buildup of _____.
( Module 6.13)
ATP
lactic acid
carbon dioxide
ADP
oxygen
In the absence of
oxygen, cells need a
way to regenerate
which compound? (
Module 6.13)
ethanol
carbon
dioxide
NAD+
lactic
acid
glucose
Muscle tissues make lactic acid from pyruvate so that you can _____. (
6.13)
get drunk
get rid of toxic pyruvate
utilize the energy in pyruvate
utilize the released CO2
Module
regenerate (oxidized) NAD+
Organisms can use other molecules as fuel for cellular respiration. When protein
molecules are used, _____ are produced as waste. ( Module 6.15)
amino groups
fatty acids
sugar molecules
molecules of lactic acid
ethanol and CO2
A gram of fat oxidized by cellular respiration produces approximately _____ as much
ATP as a gram of carbohydrate. ( Module 6.15)
half
twice
4 times
10 times
100 times
During cellular respiration, glucose is oxidized. However, an intermediate, _____, can
be siphoned off and used to synthesize fats. ( Module 6.16)
pyruvate
glyceraldeyhyde-3-phosphate
ATP
glucose
citrate
When growing in a nutrient-rich environment, bacteria can use the provided amino
acids to synthesize their proteins. However, should the environment change, they
can synthesize their amino acids using _____. ( Module 6.16)
glucose
glyceraldehyde-3-phosphate
citrate
ATP
glycerol